diff --git a/agents/kotlin-reviewer.md b/agents/kotlin-reviewer.md
new file mode 100644
index 000000000..84ac896bd
--- /dev/null
+++ b/agents/kotlin-reviewer.md
@@ -0,0 +1,159 @@
+---
+name: kotlin-reviewer
+description: Kotlin and Android/KMP code reviewer. Reviews Kotlin code for idiomatic patterns, coroutine safety, Compose best practices, clean architecture violations, and common Android pitfalls.
+tools: ["Read", "Grep", "Glob", "Bash"]
+model: sonnet
+---
+
+You are a senior Kotlin and Android/KMP code reviewer ensuring idiomatic, safe, and maintainable code.
+
+## Your Role
+
+- Review Kotlin code for idiomatic patterns and Android/KMP best practices
+- Detect coroutine misuse, Flow anti-patterns, and lifecycle bugs
+- Enforce clean architecture module boundaries
+- Identify Compose performance issues and recomposition traps
+- You DO NOT refactor or rewrite code — you report findings only
+
+## Workflow
+
+### Step 1: Gather Context
+
+Run `git diff --staged` and `git diff` to see changes. If no diff, check `git log --oneline -5`. Identify Kotlin/KTS files that changed.
+
+### Step 2: Understand Project Structure
+
+Check for:
+- `build.gradle.kts` or `settings.gradle.kts` to understand module layout
+- `CLAUDE.md` for project-specific conventions
+- Whether this is Android-only, KMP, or Compose Multiplatform
+
+### Step 2b: Security Review
+
+Apply the Kotlin/Android security guidance before continuing:
+- exported Android components, deep links, and intent filters
+- insecure crypto, WebView, and network configuration usage
+- keystore, token, and credential handling
+- platform-specific storage and permission risks
+
+If you find a CRITICAL security issue, stop the review and hand off to `security-reviewer` before doing any further analysis.
+
+### Step 3: Read and Review
+
+Read changed files fully. Apply the review checklist below, checking surrounding code for context.
+
+### Step 4: Report Findings
+
+Use the output format below. Only report issues with >80% confidence.
+
+## Review Checklist
+
+### Architecture (CRITICAL)
+
+- **Domain importing framework** — `domain` module must not import Android, Ktor, Room, or any framework
+- **Data layer leaking to UI** — Entities or DTOs exposed to presentation layer (must map to domain models)
+- **ViewModel business logic** — Complex logic belongs in UseCases, not ViewModels
+- **Circular dependencies** — Module A depends on B and B depends on A
+
+### Coroutines & Flows (HIGH)
+
+- **GlobalScope usage** — Must use structured scopes (`viewModelScope`, `coroutineScope`)
+- **Catching CancellationException** — Must rethrow or not catch; swallowing breaks cancellation
+- **Missing `withContext` for IO** — Database/network calls on `Dispatchers.Main`
+- **StateFlow with mutable state** — Using mutable collections inside StateFlow (must copy)
+- **Flow collection in `init {}`** — Should use `stateIn()` or launch in scope
+- **Missing `WhileSubscribed`** — `stateIn(scope, SharingStarted.Eagerly)` when `WhileSubscribed` is appropriate
+
+```kotlin
+// BAD — swallows cancellation
+try { fetchData() } catch (e: Exception) { log(e) }
+
+// GOOD — preserves cancellation
+try { fetchData() } catch (e: CancellationException) { throw e } catch (e: Exception) { log(e) }
+// or use runCatching and check
+```
+
+### Compose (HIGH)
+
+- **Unstable parameters** — Composables receiving mutable types cause unnecessary recomposition
+- **Side effects outside LaunchedEffect** — Network/DB calls must be in `LaunchedEffect` or ViewModel
+- **NavController passed deep** — Pass lambdas instead of `NavController` references
+- **Missing `key()` in LazyColumn** — Items without stable keys cause poor performance
+- **`remember` with missing keys** — Computation not recalculated when dependencies change
+- **Object allocation in parameters** — Creating objects inline causes recomposition
+
+```kotlin
+// BAD — new lambda every recomposition
+Button(onClick = { viewModel.doThing(item.id) })
+
+// GOOD — stable reference
+val onClick = remember(item.id) { { viewModel.doThing(item.id) } }
+Button(onClick = onClick)
+```
+
+### Kotlin Idioms (MEDIUM)
+
+- **`!!` usage** — Non-null assertion; prefer `?.`, `?:`, `requireNotNull`, or `checkNotNull`
+- **`var` where `val` works** — Prefer immutability
+- **Java-style patterns** — Static utility classes (use top-level functions), getters/setters (use properties)
+- **String concatenation** — Use string templates `"Hello $name"` instead of `"Hello " + name`
+- **`when` without exhaustive branches** — Sealed classes/interfaces should use exhaustive `when`
+- **Mutable collections exposed** — Return `List` not `MutableList` from public APIs
+
+### Android Specific (MEDIUM)
+
+- **Context leaks** — Storing `Activity` or `Fragment` references in singletons/ViewModels
+- **Missing ProGuard rules** — Serialized classes without `@Keep` or ProGuard rules
+- **Hardcoded strings** — User-facing strings not in `strings.xml` or Compose resources
+- **Missing lifecycle handling** — Collecting Flows in Activities without `repeatOnLifecycle`
+
+### Security (CRITICAL)
+
+- **Exported component exposure** — Activities, services, or receivers exported without proper guards
+- **Insecure crypto/storage** — Homegrown crypto, plaintext secrets, or weak keystore usage
+- **Unsafe WebView/network config** — JavaScript bridges, cleartext traffic, permissive trust settings
+- **Sensitive logging** — Tokens, credentials, PII, or secrets emitted to logs
+
+If any CRITICAL security issue is present, stop and escalate to `security-reviewer`.
+
+### Gradle & Build (LOW)
+
+- **Version catalog not used** — Hardcoded versions instead of `libs.versions.toml`
+- **Unnecessary dependencies** — Dependencies added but not used
+- **Missing KMP source sets** — Declaring `androidMain` code that could be `commonMain`
+
+## Output Format
+
+```
+[CRITICAL] Domain module imports Android framework
+File: domain/src/main/kotlin/com/app/domain/UserUseCase.kt:3
+Issue: `import android.content.Context` — domain must be pure Kotlin with no framework dependencies.
+Fix: Move Context-dependent logic to data or platforms layer. Pass data via repository interface.
+
+[HIGH] StateFlow holding mutable list
+File: presentation/src/main/kotlin/com/app/ui/ListViewModel.kt:25
+Issue: `_state.value.items.add(newItem)` mutates the list inside StateFlow — Compose won't detect the change.
+Fix: Use `_state.update { it.copy(items = it.items + newItem) }`
+```
+
+## Summary Format
+
+End every review with:
+
+```
+## Review Summary
+
+| Severity | Count | Status |
+|----------|-------|--------|
+| CRITICAL | 0     | pass   |
+| HIGH     | 1     | block  |
+| MEDIUM   | 2     | info   |
+| LOW      | 0     | note   |
+
+Verdict: BLOCK — HIGH issues must be fixed before merge.
+```
+
+## Approval Criteria
+
+- **Approve**: No CRITICAL or HIGH issues
+- **Block**: Any CRITICAL or HIGH issues — must fix before merge
diff --git a/commands/gradle-build.md b/commands/gradle-build.md
new file mode 100644
index 000000000..541ca1b68
--- /dev/null
+++ b/commands/gradle-build.md
@@ -0,0 +1,70 @@
+---
+description: Fix Gradle build errors for Android and KMP projects
+---
+
+# Gradle Build Fix
+
+Incrementally fix Gradle build and compilation errors for Android and Kotlin Multiplatform projects.
+
+## Step 1: Detect Build Configuration
+
+Identify the project type and run the appropriate build:
+
+| Indicator | Build Command |
+|-----------|---------------|
+| `build.gradle.kts` + `composeApp/` (KMP) | `./gradlew composeApp:compileKotlinMetadata 2>&1` |
+| `build.gradle.kts` + `app/` (Android) | `./gradlew app:compileDebugKotlin 2>&1` |
+| `settings.gradle.kts` with modules | `./gradlew assemble 2>&1` |
+| Detekt configured | `./gradlew detekt 2>&1` |
+
+Also check `gradle.properties` and `local.properties` for configuration.
+
+## Step 2: Parse and Group Errors
+
+1. Run the build command and capture output
+2. Separate Kotlin compilation errors from Gradle configuration errors
+3. Group by module and file path
+4. Sort: configuration errors first, then compilation errors by dependency order
+
+## Step 3: Fix Loop
+
+For each error:
+
+1. **Read the file** — Full context around the error line
+2. **Diagnose** — Common categories:
+   - Missing import or unresolved reference
+   - Type mismatch or incompatible types
+   - Missing dependency in `build.gradle.kts`
+   - Expect/actual mismatch (KMP)
+   - Compose compiler error
+3. **Fix minimally** — Smallest change that resolves the error
+4. **Re-run build** — Verify fix and check for new errors
+5. **Continue** — Move to next error
+
+## Step 4: Guardrails
+
+Stop and ask the user if:
+- Fix introduces more errors than it resolves
+- Same error persists after 3 attempts
+- Error requires adding new dependencies or changing module structure
+- Gradle sync itself fails (configuration-phase error)
+- Error is in generated code (Room, SQLDelight, KSP)
+
+## Step 5: Summary
+
+Report:
+- Errors fixed (module, file, description)
+- Errors remaining
+- New errors introduced (should be zero)
+- Suggested next steps
+
+## Common Gradle/KMP Fixes
+
+| Error | Fix |
+|-------|-----|
+| Unresolved reference in `commonMain` | Check if the dependency is in `commonMain.dependencies {}` |
+| Expect declaration without actual | Add `actual` implementation in each platform source set |
+| Compose compiler version mismatch | Align Kotlin and Compose compiler versions in `libs.versions.toml` |
+| Duplicate class | Check for conflicting dependencies with `./gradlew dependencies` |
+| KSP error | Run `./gradlew kspCommonMainKotlinMetadata` to regenerate |
+| Configuration cache issue | Check for non-serializable task inputs |
diff --git a/rules/kotlin/coding-style.md b/rules/kotlin/coding-style.md
new file mode 100644
index 000000000..5c5ee30cd
--- /dev/null
+++ b/rules/kotlin/coding-style.md
@@ -0,0 +1,86 @@
+---
+paths:
+  - "**/*.kt"
+  - "**/*.kts"
+---
+# Kotlin Coding Style
+
+> This file extends [common/coding-style.md](../common/coding-style.md) with Kotlin-specific content.
+
+## Formatting
+
+- **ktlint** or **Detekt** for style enforcement
+- Official Kotlin code style (`kotlin.code.style=official` in `gradle.properties`)
+
+## Immutability
+
+- Prefer `val` over `var` — default to `val` and only use `var` when mutation is required
+- Use `data class` for value types; use immutable collections (`List`, `Map`, `Set`) in public APIs
+- Copy-on-write for state updates: `state.copy(field = newValue)`
+
+## Naming
+
+Follow Kotlin conventions:
+- `camelCase` for functions and properties
+- `PascalCase` for classes, interfaces, objects, and type aliases
+- `SCREAMING_SNAKE_CASE` for constants (`const val` or `@JvmStatic`)
+- Prefix interfaces with behavior, not `I`: `Clickable` not `IClickable`
+
+## Null Safety
+
+- Never use `!!` — prefer `?.`, `?:`, `requireNotNull()`, or `checkNotNull()`
+- Use `?.let {}` for scoped null-safe operations
+- Return nullable types from functions that can legitimately have no result
+
+```kotlin
+// BAD
+val name = user!!.name
+
+// GOOD
+val name = user?.name ?: "Unknown"
+val name = requireNotNull(user) { "User must be set before accessing name" }.name
+```
+
+## Sealed Types
+
+Use sealed classes/interfaces to model closed state hierarchies:
+
+```kotlin
+sealed interface UiState<out T> {
+    data object Loading : UiState<Nothing>
+    data class Success<T>(val data: T) : UiState<T>
+    data class Error(val message: String) : UiState<Nothing>
+}
+```
+
+Always use exhaustive `when` with sealed types — no `else` branch.
+
+## Extension Functions
+
+Use extension functions for utility operations, but keep them discoverable:
+- Place in a file named after the receiver type (`StringExt.kt`, `FlowExt.kt`)
+- Keep scope limited — don't add extensions to `Any` or overly generic types
+
+## Scope Functions
+
+Use the right scope function:
+- `let` — null check + transform: `user?.let { greet(it) }`
+- `run` — compute a result using receiver: `service.run { fetch(config) }`
+- `apply` — configure an object: `builder.apply { timeout = 30 }`
+- `also` — side effects: `result.also { log(it) }`
+- Avoid deep nesting of scope functions (max 2 levels)
+
+## Error Handling
+
+- Use `Result<T>` or custom sealed types
+- Use `runCatching {}` for wrapping throwable code
+- Never catch `CancellationException` — always rethrow it
+- Avoid `try-catch` for control flow
+
+```kotlin
+// BAD — using exceptions for control flow
+val user = try { repository.getUser(id) } catch (e: NotFoundException) { null }
+
+// GOOD — nullable return
+val user: User? = repository.findUser(id)
+```
diff --git a/rules/kotlin/patterns.md b/rules/kotlin/patterns.md
new file mode 100644
index 000000000..1a09e6b7d
--- /dev/null
+++ b/rules/kotlin/patterns.md
@@ -0,0 +1,146 @@
+---
+paths:
+  - "**/*.kt"
+  - "**/*.kts"
+---
+# Kotlin Patterns
+
+> This file extends [common/patterns.md](../common/patterns.md) with Kotlin and Android/KMP-specific content.
+
+## Dependency Injection
+
+Prefer constructor injection. Use Koin (KMP) or Hilt (Android-only):
+
+```kotlin
+// Koin — declare modules
+val dataModule = module {
+    single<ItemRepository> { ItemRepositoryImpl(get(), get()) }
+    factory { GetItemsUseCase(get()) }
+    viewModelOf(::ItemListViewModel)
+}
+
+// Hilt — annotations
+@HiltViewModel
+class ItemListViewModel @Inject constructor(
+    private val getItems: GetItemsUseCase
+) : ViewModel()
+```
+
+## ViewModel Pattern
+
+Single state object, event sink, one-way data flow:
+
+```kotlin
+data class ScreenState(
+    val items: List<Item> = emptyList(),
+    val isLoading: Boolean = false
+)
+
+class ScreenViewModel(private val useCase: GetItemsUseCase) : ViewModel() {
+    private val _state = MutableStateFlow(ScreenState())
+    val state = _state.asStateFlow()
+
+    fun onEvent(event: ScreenEvent) {
+        when (event) {
+            is ScreenEvent.Load -> load()
+            is ScreenEvent.Delete -> delete(event.id)
+        }
+    }
+}
+```
+
+## Repository Pattern
+
+- `suspend` functions return `Result<T>` or custom error type
+- `Flow` for reactive streams
+- Coordinate local + remote data sources
+
+```kotlin
+interface ItemRepository {
+    suspend fun getById(id: String): Result<Item>
+    suspend fun getAll(): Result<List<Item>>
+    fun observeAll(): Flow<List<Item>>
+}
+```
+
+## UseCase Pattern
+
+Single responsibility, `operator fun invoke`:
+
+```kotlin
+class GetItemUseCase(private val repository: ItemRepository) {
+    suspend operator fun invoke(id: String): Result<Item> {
+        return repository.getById(id)
+    }
+}
+
+class GetItemsUseCase(private val repository: ItemRepository) {
+    suspend operator fun invoke(): Result<List<Item>> {
+        return repository.getAll()
+    }
+}
+```
+
+## expect/actual (KMP)
+
+Use for platform-specific implementations:
+
+```kotlin
+// commonMain
+expect fun platformName(): String
+expect class SecureStorage {
+    fun save(key: String, value: String)
+    fun get(key: String): String?
+}
+
+// androidMain
+actual fun platformName(): String = "Android"
+actual class SecureStorage {
+    actual fun save(key: String, value: String) { /* EncryptedSharedPreferences */ }
+    actual fun get(key: String): String? = null /* ... */
+}
+
+// iosMain
+actual fun platformName(): String = "iOS"
+actual class SecureStorage {
+    actual fun save(key: String, value: String) { /* Keychain */ }
+    actual fun get(key: String): String? = null /* ... */
+}
+```
+
+## Coroutine Patterns
+
+- Use `viewModelScope` in ViewModels, `coroutineScope` for structured child work
+- Use `stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), initialValue)` for StateFlow from cold Flows
+- Use `supervisorScope` when child failures should be independent
+
+## Builder Pattern with DSL
+
+```kotlin
+class HttpClientConfig {
+    var baseUrl: String = ""
+    var timeout: Long = 30_000
+    private val interceptors = mutableListOf<Interceptor>()
+
+    fun interceptor(block: () -> Interceptor) {
+        interceptors.add(block())
+    }
+}
+
+fun httpClient(block: HttpClientConfig.() -> Unit): HttpClient {
+    val config = HttpClientConfig().apply(block)
+    return HttpClient(config)
+}
+
+// Usage
+val client = httpClient {
+    baseUrl = "https://api.example.com"
+    timeout = 15_000
+    interceptor { AuthInterceptor(tokenProvider) }
+}
+```
+
+## References
+
+See skill: `kotlin-coroutines-flows` for detailed coroutine patterns.
+See skill: `android-clean-architecture` for module and layer patterns.
diff --git a/rules/kotlin/security.md b/rules/kotlin/security.md
new file mode 100644
index 000000000..a212211d2
--- /dev/null
+++ b/rules/kotlin/security.md
@@ -0,0 +1,82 @@
+---
+paths:
+  - "**/*.kt"
+  - "**/*.kts"
+---
+# Kotlin Security
+
+> This file extends [common/security.md](../common/security.md) with Kotlin and Android/KMP-specific content.
+
+## Secrets Management
+
+- Never hardcode API keys, tokens, or credentials in source code
+- Use `local.properties` (git-ignored) for local development secrets
+- Use `BuildConfig` fields generated from CI secrets for release builds
+- Use `EncryptedSharedPreferences` (Android) or Keychain (iOS) for runtime secret storage
+
+```kotlin
+// BAD
+val apiKey = "sk-abc123..."
+
+// GOOD — from BuildConfig (generated at build time)
+val apiKey = BuildConfig.API_KEY
+
+// GOOD — from secure storage at runtime
+val token = secureStorage.get("auth_token")
+```
+
+## Network Security
+
+- Use HTTPS exclusively — configure `network_security_config.xml` to block cleartext
+- Pin certificates for sensitive endpoints using OkHttp `CertificatePinner` or Ktor equivalent
+- Set timeouts on all HTTP clients — never leave defaults (which may be infinite)
+- Validate and sanitize all server responses before use
+
+```xml
+<!-- res/xml/network_security_config.xml -->
+<network-security-config>
+    <base-config cleartextTrafficPermitted="false" />
+</network-security-config>
+```
+
+## Input Validation
+
+- Validate all user input before processing or sending to API
+- Use parameterized queries for Room/SQLDelight — never concatenate user input into SQL
+- Sanitize file paths from user input to prevent path traversal
+
+```kotlin
+// BAD — SQL injection
+@Query("SELECT * FROM items WHERE name = '$input'")
+
+// GOOD — parameterized
+@Query("SELECT * FROM items WHERE name = :input")
+fun findByName(input: String): List<ItemEntity>
+```
+
+## Data Protection
+
+- Use `EncryptedSharedPreferences` for sensitive key-value data on Android
+- Use `@Serializable` with explicit field names — don't leak internal property names
+- Clear sensitive data from memory when no longer needed
+- Use `@Keep` or ProGuard rules for serialized classes to prevent name mangling
+
+## Authentication
+
+- Store tokens in secure storage, not in plain SharedPreferences
+- Implement token refresh with proper 401/403 handling
+- Clear all auth state on logout (tokens, cached user data, cookies)
+- Use biometric authentication (`BiometricPrompt`) for sensitive operations
+
+## ProGuard / R8
+
+- Keep rules for all serialized models (`@Serializable`, Gson, Moshi)
+- Keep rules for reflection-based libraries (Koin, Retrofit)
+- Test release builds — obfuscation can break serialization silently
+
+## WebView Security
+
+- Disable JavaScript unless explicitly needed: `settings.javaScriptEnabled = false`
+- Validate URLs before loading in WebView
+- Never expose `@JavascriptInterface` methods that access sensitive data
+- Use `WebViewClient.shouldOverrideUrlLoading()` to control navigation
diff --git a/rules/kotlin/testing.md b/rules/kotlin/testing.md
new file mode 100644
index 000000000..cdf973345
--- /dev/null
+++ b/rules/kotlin/testing.md
@@ -0,0 +1,128 @@
+---
+paths:
+  - "**/*.kt"
+  - "**/*.kts"
+---
+# Kotlin Testing
+
+> This file extends [common/testing.md](../common/testing.md) with Kotlin and Android/KMP-specific content.
+
+## Test Framework
+
+- **kotlin.test** for multiplatform (KMP) — `@Test`, `assertEquals`, `assertTrue`
+- **JUnit 4/5** for Android-specific tests
+- **Turbine** for testing Flows and StateFlow
+- **kotlinx-coroutines-test** for coroutine testing (`runTest`, `TestDispatcher`)
+
+## ViewModel Testing with Turbine
+
+```kotlin
+@Test
+fun `loading state emitted then data`() = runTest {
+    val repo = FakeItemRepository()
+    repo.addItem(testItem)
+    val viewModel = ItemListViewModel(GetItemsUseCase(repo))
+
+    viewModel.state.test {
+        assertEquals(ItemListState(), awaitItem())     // initial state
+        viewModel.onEvent(ItemListEvent.Load)
+        assertTrue(awaitItem().isLoading)               // loading
+        assertEquals(listOf(testItem), awaitItem().items) // loaded
+    }
+}
+```
+
+## Fakes Over Mocks
+
+Prefer hand-written fakes over mocking frameworks:
+
+```kotlin
+class FakeItemRepository : ItemRepository {
+    private val items = mutableListOf<Item>()
+    var fetchError: Throwable? = null
+
+    override suspend fun getAll(): Result<List<Item>> {
+        fetchError?.let { return Result.failure(it) }
+        return Result.success(items.toList())
+    }
+
+    override fun observeAll(): Flow<List<Item>> = flowOf(items.toList())
+
+    fun addItem(item: Item) { items.add(item) }
+}
+```
+
+## Coroutine Testing
+
+```kotlin
+@Test
+fun `parallel operations complete`() = runTest {
+    val repo = FakeRepository()
+    val result = loadDashboard(repo)
+    advanceUntilIdle()
+    assertNotNull(result.items)
+    assertNotNull(result.stats)
+}
+```
+
+Use `runTest` — it auto-advances virtual time and provides `TestScope`.
+
+## Ktor MockEngine
+
+```kotlin
+val mockEngine = MockEngine { request ->
+    when (request.url.encodedPath) {
+        "/api/items" -> respond(
+            content = Json.encodeToString(testItems),
+            headers = headersOf(HttpHeaders.ContentType, ContentType.Application.Json.toString())
+        )
+        else -> respondError(HttpStatusCode.NotFound)
+    }
+}
+
+val client = HttpClient(mockEngine) {
+    install(ContentNegotiation) { json() }
+}
+```
+
+## Room/SQLDelight Testing
+
+- Room: Use `Room.inMemoryDatabaseBuilder()` for in-memory testing
+- SQLDelight: Use `JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)` for JVM tests
+
+```kotlin
+@Test
+fun `insert and query items`() = runTest {
+    val driver = JdbcSqliteDriver(JdbcSqliteDriver.IN_MEMORY)
+    Database.Schema.create(driver)
+    val db = Database(driver)
+
+    db.itemQueries.insert("1", "Sample Item", "description")
+    val items = db.itemQueries.getAll().executeAsList()
+    assertEquals(1, items.size)
+}
+```
+
+## Test Naming
+
+Use backtick-quoted descriptive names:
+
+```kotlin
+@Test
+fun `search with empty query returns all items`() = runTest { }
+
+@Test
+fun `delete item emits updated list without deleted item`() = runTest { }
+```
+
+## Test Organization
+
+```
+src/
+├── commonTest/kotlin/     # Shared tests (ViewModel, UseCase, Repository)
+├── androidUnitTest/kotlin/ # Android unit tests (JUnit)
+├── androidInstrumentedTest/kotlin/  # Instrumented tests (Room, UI)
+└── iosTest/kotlin/        # iOS-specific tests
+```
+
+Minimum test coverage: ViewModel + UseCase for every feature.
diff --git a/skills/android-clean-architecture/SKILL.md b/skills/android-clean-architecture/SKILL.md
new file mode 100644
index 000000000..1b4963f5d
--- /dev/null
+++ b/skills/android-clean-architecture/SKILL.md
@@ -0,0 +1,339 @@
+---
+name: android-clean-architecture
+description: Clean Architecture patterns for Android and Kotlin Multiplatform projects — module structure, dependency rules, UseCases, Repositories, and data layer patterns.
+origin: ECC
+---
+
+# Android Clean Architecture
+
+Clean Architecture patterns for Android and KMP projects. Covers module boundaries, dependency inversion, UseCase/Repository patterns, and data layer design with Room, SQLDelight, and Ktor.
+
+## When to Activate
+
+- Structuring Android or KMP project modules
+- Implementing UseCases, Repositories, or DataSources
+- Designing data flow between layers (domain, data, presentation)
+- Setting up dependency injection with Koin or Hilt
+- Working with Room, SQLDelight, or Ktor in a layered architecture
+
+## Module Structure
+
+### Recommended Layout
+
+```
+project/
+├── app/                  # Android entry point, DI wiring, Application class
+├── core/                 # Shared utilities, base classes, error types
+├── domain/               # UseCases, domain models, repository interfaces (pure Kotlin)
+├── data/                 # Repository implementations, DataSources, DB, network
+├── presentation/         # Screens, ViewModels, UI models, navigation
+├── design-system/        # Reusable Compose components, theme, typography
+└── feature/              # Feature modules (optional, for larger projects)
+    ├── auth/
+    ├── settings/
+    └── profile/
+```
+
+### Dependency Rules
+
+```
+app → presentation, domain, data, core
+presentation → domain, design-system, core
+data → domain, core
+domain → core (or no dependencies)
+core → (nothing)
+```
+
+**Critical**: `domain` must NEVER depend on `data`, `presentation`, or any framework. It contains pure Kotlin only.
+
+## Domain Layer
+
+### UseCase Pattern
+
+Each UseCase represents one business operation. Use `operator fun invoke` for clean call sites:
+
+```kotlin
+class GetItemsByCategoryUseCase(
+    private val repository: ItemRepository
+) {
+    suspend operator fun invoke(category: String): Result<List<Item>> {
+        return repository.getItemsByCategory(category)
+    }
+}
+
+// Flow-based UseCase for reactive streams
+class ObserveUserProgressUseCase(
+    private val repository: UserRepository
+) {
+    operator fun invoke(userId: String): Flow<UserProgress> {
+        return repository.observeProgress(userId)
+    }
+}
+```
+
+### Domain Models
+
+Domain models are plain Kotlin data classes — no framework annotations:
+
+```kotlin
+data class Item(
+    val id: String,
+    val title: String,
+    val description: String,
+    val tags: List<String>,
+    val status: Status,
+    val category: String
+)
+
+enum class Status { DRAFT, ACTIVE, ARCHIVED }
+```
+
+### Repository Interfaces
+
+Defined in domain, implemented in data:
+
+```kotlin
+interface ItemRepository {
+    suspend fun getItemsByCategory(category: String): Result<List<Item>>
+    suspend fun saveItem(item: Item): Result<Unit>
+    fun observeItems(): Flow<List<Item>>
+}
+```
+
+## Data Layer
+
+### Repository Implementation
+
+Coordinates between local and remote data sources:
+
+```kotlin
+class ItemRepositoryImpl(
+    private val localDataSource: ItemLocalDataSource,
+    private val remoteDataSource: ItemRemoteDataSource
+) : ItemRepository {
+
+    override suspend fun getItemsByCategory(category: String): Result<List<Item>> {
+        return runCatching {
+            val remote = remoteDataSource.fetchItems(category)
+            localDataSource.insertItems(remote.map { it.toEntity() })
+            localDataSource.getItemsByCategory(category).map { it.toDomain() }
+        }
+    }
+
+    override suspend fun saveItem(item: Item): Result<Unit> {
+        return runCatching {
+            localDataSource.insertItems(listOf(item.toEntity()))
+        }
+    }
+
+    override fun observeItems(): Flow<List<Item>> {
+        return localDataSource.observeAll().map { entities ->
+            entities.map { it.toDomain() }
+        }
+    }
+}
+```
+
+### Mapper Pattern
+
+Keep mappers as extension functions near the data models:
+
+```kotlin
+// In data layer
+fun ItemEntity.toDomain() = Item(
+    id = id,
+    title = title,
+    description = description,
+    tags = tags.split("|"),
+    status = Status.valueOf(status),
+    category = category
+)
+
+fun ItemDto.toEntity() = ItemEntity(
+    id = id,
+    title = title,
+    description = description,
+    tags = tags.joinToString("|"),
+    status = status,
+    category = category
+)
+```
+
+### Room Database (Android)
+
+```kotlin
+@Entity(tableName = "items")
+data class ItemEntity(
+    @PrimaryKey val id: String,
+    val title: String,
+    val description: String,
+    val tags: String,
+    val status: String,
+    val category: String
+)
+
+@Dao
+interface ItemDao {
+    @Query("SELECT * FROM items WHERE category = :category")
+    suspend fun getByCategory(category: String): List<ItemEntity>
+
+    @Upsert
+    suspend fun upsert(items: List<ItemEntity>)
+
+    @Query("SELECT * FROM items")
+    fun observeAll(): Flow<List<ItemEntity>>
+}
+```
+
+### SQLDelight (KMP)
+
+```sql
+-- Item.sq
+CREATE TABLE ItemEntity (
+    id TEXT NOT NULL PRIMARY KEY,
+    title TEXT NOT NULL,
+    description TEXT NOT NULL,
+    tags TEXT NOT NULL,
+    status TEXT NOT NULL,
+    category TEXT NOT NULL
+);
+
+getByCategory:
+SELECT * FROM ItemEntity WHERE category = ?;
+
+upsert:
+INSERT OR REPLACE INTO ItemEntity (id, title, description, tags, status, category)
+VALUES (?, ?, ?, ?, ?, ?);
+
+observeAll:
+SELECT * FROM ItemEntity;
+```
+
+### Ktor Network Client (KMP)
+
+```kotlin
+class ItemRemoteDataSource(private val client: HttpClient) {
+
+    suspend fun fetchItems(category: String): List<ItemDto> {
+        return client.get("api/items") {
+            parameter("category", category)
+        }.body()
+    }
+}
+
+// HttpClient setup with content negotiation
+val httpClient = HttpClient {
+    install(ContentNegotiation) { json(Json { ignoreUnknownKeys = true }) }
+    install(Logging) { level = LogLevel.HEADERS }
+    defaultRequest { url("https://api.example.com/") }
+}
+```
+
+## Dependency Injection
+
+### Koin (KMP-friendly)
+
+```kotlin
+// Domain module
+val domainModule = module {
+    factory { GetItemsByCategoryUseCase(get()) }
+    factory { ObserveUserProgressUseCase(get()) }
+}
+
+// Data module
+val dataModule = module {
+    single<ItemRepository> { ItemRepositoryImpl(get(), get()) }
+    single { ItemLocalDataSource(get()) }
+    single { ItemRemoteDataSource(get()) }
+}
+
+// Presentation module
+val presentationModule = module {
+    viewModelOf(::ItemListViewModel)
+    viewModelOf(::DashboardViewModel)
+}
+```
+
+### Hilt (Android-only)
+
+```kotlin
+@Module
+@InstallIn(SingletonComponent::class)
+abstract class RepositoryModule {
+    @Binds
+    abstract fun bindItemRepository(impl: ItemRepositoryImpl): ItemRepository
+}
+
+@HiltViewModel
+class ItemListViewModel @Inject constructor(
+    private val getItems: GetItemsByCategoryUseCase
+) : ViewModel()
+```
+
+## Error Handling
+
+### Result/Try Pattern
+
+Use `Result<T>` or a custom sealed type for error propagation:
+
+```kotlin
+sealed interface Try<out T> {
+    data class Success<T>(val value: T) : Try<T>
+    data class Failure(val error: AppError) : Try<Nothing>
+}
+
+sealed interface AppError {
+    data class Network(val message: String) : AppError
+    data class Database(val message: String) : AppError
+    data object Unauthorized : AppError
+}
+
+// In ViewModel — map to UI state
+viewModelScope.launch {
+    when (val result = getItems(category)) {
+        is Try.Success -> _state.update { it.copy(items = result.value, isLoading = false) }
+        is Try.Failure -> _state.update { it.copy(error = result.error.toMessage(), isLoading = false) }
+    }
+}
+```
+
+## Convention Plugins (Gradle)
+
+For KMP projects, use convention plugins to reduce build file duplication:
+
+```kotlin
+// build-logic/src/main/kotlin/kmp-library.gradle.kts
+plugins {
+    id("org.jetbrains.kotlin.multiplatform")
+}
+
+kotlin {
+    androidTarget()
+    iosX64(); iosArm64(); iosSimulatorArm64()
+    sourceSets {
+        commonMain.dependencies { /* shared deps */ }
+        commonTest.dependencies { implementation(kotlin("test")) }
+    }
+}
+```
+
+Apply in modules:
+
+```kotlin
+// domain/build.gradle.kts
+plugins { id("kmp-library") }
+```
+
+## Anti-Patterns to Avoid
+
+- Importing Android framework classes in `domain` — keep it pure Kotlin
+- Exposing database entities or DTOs to the UI layer — always map to domain models
+- Putting business logic in ViewModels — extract to UseCases
+- Using `GlobalScope` or unstructured coroutines — use `viewModelScope` or structured concurrency
+- Fat repository implementations — split into focused DataSources
+- Circular module dependencies — if A depends on B, B must not depend on A
+
+## References
+
+See skill: `compose-multiplatform-patterns` for UI patterns.
+See skill: `kotlin-coroutines-flows` for async patterns.
diff --git a/skills/compose-multiplatform-patterns/SKILL.md b/skills/compose-multiplatform-patterns/SKILL.md
new file mode 100644
index 000000000..f4caec1e0
--- /dev/null
+++ b/skills/compose-multiplatform-patterns/SKILL.md
@@ -0,0 +1,299 @@
+---
+name: compose-multiplatform-patterns
+description: Compose Multiplatform and Jetpack Compose patterns for KMP projects — state management, navigation, theming, performance, and platform-specific UI.
+origin: ECC
+---
+
+# Compose Multiplatform Patterns
+
+Patterns for building shared UI across Android, iOS, Desktop, and Web using Compose Multiplatform and Jetpack Compose. Covers state management, navigation, theming, and performance.
+
+## When to Activate
+
+- Building Compose UI (Jetpack Compose or Compose Multiplatform)
+- Managing UI state with ViewModels and Compose state
+- Implementing navigation in KMP or Android projects
+- Designing reusable composables and design systems
+- Optimizing recomposition and rendering performance
+
+## State Management
+
+### ViewModel + Single State Object
+
+Use a single data class for screen state. Expose it as `StateFlow` and collect in Compose:
+
+```kotlin
+data class ItemListState(
+    val items: List<Item> = emptyList(),
+    val isLoading: Boolean = false,
+    val error: String? = null,
+    val searchQuery: String = ""
+)
+
+class ItemListViewModel(
+    private val getItems: GetItemsUseCase
+) : ViewModel() {
+    private val _state = MutableStateFlow(ItemListState())
+    val state: StateFlow<ItemListState> = _state.asStateFlow()
+
+    fun onSearch(query: String) {
+        _state.update { it.copy(searchQuery = query) }
+        loadItems(query)
+    }
+
+    private fun loadItems(query: String) {
+        viewModelScope.launch {
+            _state.update { it.copy(isLoading = true) }
+            getItems(query).fold(
+                onSuccess = { items -> _state.update { it.copy(items = items, isLoading = false) } },
+                onFailure = { e -> _state.update { it.copy(error = e.message, isLoading = false) } }
+            )
+        }
+    }
+}
+```
+
+### Collecting State in Compose
+
+```kotlin
+@Composable
+fun ItemListScreen(viewModel: ItemListViewModel = koinViewModel()) {
+    val state by viewModel.state.collectAsStateWithLifecycle()
+
+    ItemListContent(
+        state = state,
+        onSearch = viewModel::onSearch
+    )
+}
+
+@Composable
+private fun ItemListContent(
+    state: ItemListState,
+    onSearch: (String) -> Unit
+) {
+    // Stateless composable — easy to preview and test
+}
+```
+
+### Event Sink Pattern
+
+For complex screens, use a sealed interface for events instead of multiple callback lambdas:
+
+```kotlin
+sealed interface ItemListEvent {
+    data class Search(val query: String) : ItemListEvent
+    data class Delete(val itemId: String) : ItemListEvent
+    data object Refresh : ItemListEvent
+}
+
+// In ViewModel
+fun onEvent(event: ItemListEvent) {
+    when (event) {
+        is ItemListEvent.Search -> onSearch(event.query)
+        is ItemListEvent.Delete -> deleteItem(event.itemId)
+        is ItemListEvent.Refresh -> loadItems(_state.value.searchQuery)
+    }
+}
+
+// In Composable — single lambda instead of many
+ItemListContent(
+    state = state,
+    onEvent = viewModel::onEvent
+)
+```
+
+## Navigation
+
+### Type-Safe Navigation (Compose Navigation 2.8+)
+
+Define routes as `@Serializable` objects:
+
+```kotlin
+@Serializable data object HomeRoute
+@Serializable data class DetailRoute(val id: String)
+@Serializable data object SettingsRoute
+
+@Composable
+fun AppNavHost(navController: NavHostController = rememberNavController()) {
+    NavHost(navController, startDestination = HomeRoute) {
+        composable<HomeRoute> {
+            HomeScreen(onNavigateToDetail = { id -> navController.navigate(DetailRoute(id)) })
+        }
+        composable<DetailRoute> { backStackEntry ->
+            val route = backStackEntry.toRoute<DetailRoute>()
+            DetailScreen(id = route.id)
+        }
+        composable<SettingsRoute> { SettingsScreen() }
+    }
+}
+```
+
+### Dialog and Bottom Sheet Navigation
+
+Use `dialog()` and overlay patterns instead of imperative show/hide:
+
+```kotlin
+NavHost(navController, startDestination = HomeRoute) {
+    composable<HomeRoute> { /* ... */ }
+    dialog<ConfirmDeleteRoute> { backStackEntry ->
+        val route = backStackEntry.toRoute<ConfirmDeleteRoute>()
+        ConfirmDeleteDialog(
+            itemId = route.itemId,
+            onConfirm = { navController.popBackStack() },
+            onDismiss = { navController.popBackStack() }
+        )
+    }
+}
+```
+
+## Composable Design
+
+### Slot-Based APIs
+
+Design composables with slot parameters for flexibility:
+
+```kotlin
+@Composable
+fun AppCard(
+    modifier: Modifier = Modifier,
+    header: @Composable () -> Unit = {},
+    content: @Composable ColumnScope.() -> Unit,
+    actions: @Composable RowScope.() -> Unit = {}
+) {
+    Card(modifier = modifier) {
+        Column {
+            header()
+            Column(content = content)
+            Row(horizontalArrangement = Arrangement.End, content = actions)
+        }
+    }
+}
+```
+
+### Modifier Ordering
+
+Modifier order matters — apply in this sequence:
+
+```kotlin
+Text(
+    text = "Hello",
+    modifier = Modifier
+        .padding(16.dp)          // 1. Layout (padding, size)
+        .clip(RoundedCornerShape(8.dp))  // 2. Shape
+        .background(Color.White) // 3. Drawing (background, border)
+        .clickable { }           // 4. Interaction
+)
+```
+
+## KMP Platform-Specific UI
+
+### expect/actual for Platform Composables
+
+```kotlin
+// commonMain
+@Composable
+expect fun PlatformStatusBar(darkIcons: Boolean)
+
+// androidMain
+@Composable
+actual fun PlatformStatusBar(darkIcons: Boolean) {
+    val systemUiController = rememberSystemUiController()
+    SideEffect { systemUiController.setStatusBarColor(Color.Transparent, darkIcons) }
+}
+
+// iosMain
+@Composable
+actual fun PlatformStatusBar(darkIcons: Boolean) {
+    // iOS handles this via UIKit interop or Info.plist
+}
+```
+
+## Performance
+
+### Stable Types for Skippable Recomposition
+
+Mark classes as `@Stable` or `@Immutable` when all properties are stable:
+
+```kotlin
+@Immutable
+data class ItemUiModel(
+    val id: String,
+    val title: String,
+    val description: String,
+    val progress: Float
+)
+```
+
+### Use `key()` and Lazy Lists Correctly
+
+```kotlin
+LazyColumn {
+    items(
+        items = items,
+        key = { it.id }  // Stable keys enable item reuse and animations
+    ) { item ->
+        ItemRow(item = item)
+    }
+}
+```
+
+### Defer Reads with `derivedStateOf`
+
+```kotlin
+val listState = rememberLazyListState()
+val showScrollToTop by remember {
+    derivedStateOf { listState.firstVisibleItemIndex > 5 }
+}
+```
+
+### Avoid Allocations in Recomposition
+
+```kotlin
+// BAD — new lambda and list every recomposition
+items.filter { it.isActive }.forEach { ActiveItem(it, onClick = { handle(it) }) }
+
+// GOOD — key each item so callbacks stay attached to the right row
+val activeItems = remember(items) { items.filter { it.isActive } }
+activeItems.forEach { item ->
+    key(item.id) {
+        ActiveItem(item, onClick = { handle(item) })
+    }
+}
+```
+
+## Theming
+
+### Material 3 Dynamic Theming
+
+```kotlin
+@Composable
+fun AppTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    dynamicColor: Boolean = true,
+    content: @Composable () -> Unit
+) {
+    val colorScheme = when {
+        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            if (darkTheme) dynamicDarkColorScheme(LocalContext.current)
+            else dynamicLightColorScheme(LocalContext.current)
+        }
+        darkTheme -> darkColorScheme()
+        else -> lightColorScheme()
+    }
+
+    MaterialTheme(colorScheme = colorScheme, content = content)
+}
+```
+
+## Anti-Patterns to Avoid
+
+- Using `mutableStateOf` in ViewModels when `MutableStateFlow` with `collectAsStateWithLifecycle` is safer for lifecycle
+- Passing `NavController` deep into composables — pass lambda callbacks instead
+- Heavy computation inside `@Composable` functions — move to ViewModel or `remember {}`
+- Using `LaunchedEffect(Unit)` as a substitute for ViewModel init — it re-runs on configuration change in some setups
+- Creating new object instances in composable parameters — causes unnecessary recomposition
+
+## References
+
+See skill: `android-clean-architecture` for module structure and layering.
+See skill: `kotlin-coroutines-flows` for coroutine and Flow patterns.
diff --git a/skills/kotlin-coroutines-flows/SKILL.md b/skills/kotlin-coroutines-flows/SKILL.md
new file mode 100644
index 000000000..4108aaccf
--- /dev/null
+++ b/skills/kotlin-coroutines-flows/SKILL.md
@@ -0,0 +1,284 @@
+---
+name: kotlin-coroutines-flows
+description: Kotlin Coroutines and Flow patterns for Android and KMP — structured concurrency, Flow operators, StateFlow, error handling, and testing.
+origin: ECC
+---
+
+# Kotlin Coroutines & Flows
+
+Patterns for structured concurrency, Flow-based reactive streams, and coroutine testing in Android and Kotlin Multiplatform projects.
+
+## When to Activate
+
+- Writing async code with Kotlin coroutines
+- Using Flow, StateFlow, or SharedFlow for reactive data
+- Handling concurrent operations (parallel loading, debounce, retry)
+- Testing coroutines and Flows
+- Managing coroutine scopes and cancellation
+
+## Structured Concurrency
+
+### Scope Hierarchy
+
+```
+Application
+  └── viewModelScope (ViewModel)
+        └── coroutineScope { } (structured child)
+              ├── async { } (concurrent task)
+              └── async { } (concurrent task)
+```
+
+Always use structured concurrency — never `GlobalScope`:
+
+```kotlin
+// BAD
+GlobalScope.launch { fetchData() }
+
+// GOOD — scoped to ViewModel lifecycle
+viewModelScope.launch { fetchData() }
+
+// GOOD — scoped to composable lifecycle
+LaunchedEffect(key) { fetchData() }
+```
+
+### Parallel Decomposition
+
+Use `coroutineScope` + `async` for parallel work:
+
+```kotlin
+suspend fun loadDashboard(): Dashboard = coroutineScope {
+    val items = async { itemRepository.getRecent() }
+    val stats = async { statsRepository.getToday() }
+    val profile = async { userRepository.getCurrent() }
+    Dashboard(
+        items = items.await(),
+        stats = stats.await(),
+        profile = profile.await()
+    )
+}
+```
+
+### SupervisorScope
+
+Use `supervisorScope` when child failures should not cancel siblings:
+
+```kotlin
+suspend fun syncAll() = supervisorScope {
+    launch { syncItems() }       // failure here won't cancel syncStats
+    launch { syncStats() }
+    launch { syncSettings() }
+}
+```
+
+## Flow Patterns
+
+### Cold Flow — One-Shot to Stream Conversion
+
+```kotlin
+fun observeItems(): Flow<List<Item>> = flow {
+    // Re-emits whenever the database changes
+    itemDao.observeAll()
+        .map { entities -> entities.map { it.toDomain() } }
+        .collect { emit(it) }
+}
+```
+
+### StateFlow for UI State
+
+```kotlin
+class DashboardViewModel(
+    observeProgress: ObserveUserProgressUseCase
+) : ViewModel() {
+    val progress: StateFlow<UserProgress> = observeProgress()
+        .stateIn(
+            scope = viewModelScope,
+            started = SharingStarted.WhileSubscribed(5_000),
+            initialValue = UserProgress.EMPTY
+        )
+}
+```
+
+`WhileSubscribed(5_000)` keeps the upstream active for 5 seconds after the last subscriber leaves — survives configuration changes without restarting.
+
+### Combining Multiple Flows
+
+```kotlin
+val uiState: StateFlow<HomeState> = combine(
+    itemRepository.observeItems(),
+    settingsRepository.observeTheme(),
+    userRepository.observeProfile()
+) { items, theme, profile ->
+    HomeState(items = items, theme = theme, profile = profile)
+}.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), HomeState())
+```
+
+### Flow Operators
+
+```kotlin
+// Debounce search input
+searchQuery
+    .debounce(300)
+    .distinctUntilChanged()
+    .flatMapLatest { query -> repository.search(query) }
+    .catch { emit(emptyList()) }
+    .collect { results -> _state.update { it.copy(results = results) } }
+
+// Retry with exponential backoff
+fun fetchWithRetry(): Flow<Data> = flow { emit(api.fetch()) }
+    .retryWhen { cause, attempt ->
+        if (cause is IOException && attempt < 3) {
+            delay(1000L * (1 shl attempt.toInt()))
+            true
+        } else {
+            false
+        }
+    }
+```
+
+### SharedFlow for One-Time Events
+
+```kotlin
+class ItemListViewModel : ViewModel() {
+    private val _effects = MutableSharedFlow<Effect>()
+    val effects: SharedFlow<Effect> = _effects.asSharedFlow()
+
+    sealed interface Effect {
+        data class ShowSnackbar(val message: String) : Effect
+        data class NavigateTo(val route: String) : Effect
+    }
+
+    private fun deleteItem(id: String) {
+        viewModelScope.launch {
+            repository.delete(id)
+            _effects.emit(Effect.ShowSnackbar("Item deleted"))
+        }
+    }
+}
+
+// Collect in Composable
+LaunchedEffect(Unit) {
+    viewModel.effects.collect { effect ->
+        when (effect) {
+            is Effect.ShowSnackbar -> snackbarHostState.showSnackbar(effect.message)
+            is Effect.NavigateTo -> navController.navigate(effect.route)
+        }
+    }
+}
+```
+
+## Dispatchers
+
+```kotlin
+// CPU-intensive work
+withContext(Dispatchers.Default) { parseJson(largePayload) }
+
+// IO-bound work
+withContext(Dispatchers.IO) { database.query() }
+
+// Main thread (UI) — default in viewModelScope
+withContext(Dispatchers.Main) { updateUi() }
+```
+
+In KMP, use `Dispatchers.Default` and `Dispatchers.Main` (available on all platforms). `Dispatchers.IO` is JVM/Android only — use `Dispatchers.Default` on other platforms or provide via DI.
+
+## Cancellation
+
+### Cooperative Cancellation
+
+Long-running loops must check for cancellation:
+
+```kotlin
+suspend fun processItems(items: List<Item>) = coroutineScope {
+    for (item in items) {
+        ensureActive()  // throws CancellationException if cancelled
+        process(item)
+    }
+}
+```
+
+### Cleanup with try/finally
+
+```kotlin
+viewModelScope.launch {
+    try {
+        _state.update { it.copy(isLoading = true) }
+        val data = repository.fetch()
+        _state.update { it.copy(data = data) }
+    } finally {
+        _state.update { it.copy(isLoading = false) }  // always runs, even on cancellation
+    }
+}
+```
+
+## Testing
+
+### Testing StateFlow with Turbine
+
+```kotlin
+@Test
+fun `search updates item list`() = runTest {
+    val fakeRepository = FakeItemRepository().apply { emit(testItems) }
+    val viewModel = ItemListViewModel(GetItemsUseCase(fakeRepository))
+
+    viewModel.state.test {
+        assertEquals(ItemListState(), awaitItem())  // initial
+
+        viewModel.onSearch("query")
+        val loading = awaitItem()
+        assertTrue(loading.isLoading)
+
+        val loaded = awaitItem()
+        assertFalse(loaded.isLoading)
+        assertEquals(1, loaded.items.size)
+    }
+}
+```
+
+### Testing with TestDispatcher
+
+```kotlin
+@Test
+fun `parallel load completes correctly`() = runTest {
+    val viewModel = DashboardViewModel(
+        itemRepo = FakeItemRepo(),
+        statsRepo = FakeStatsRepo()
+    )
+
+    viewModel.load()
+    advanceUntilIdle()
+
+    val state = viewModel.state.value
+    assertNotNull(state.items)
+    assertNotNull(state.stats)
+}
+```
+
+### Faking Flows
+
+```kotlin
+class FakeItemRepository : ItemRepository {
+    private val _items = MutableStateFlow<List<Item>>(emptyList())
+
+    override fun observeItems(): Flow<List<Item>> = _items
+
+    fun emit(items: List<Item>) { _items.value = items }
+
+    override suspend fun getItemsByCategory(category: String): Result<List<Item>> {
+        return Result.success(_items.value.filter { it.category == category })
+    }
+}
+```
+
+## Anti-Patterns to Avoid
+
+- Using `GlobalScope` — leaks coroutines, no structured cancellation
+- Collecting Flows in `init {}` without a scope — use `viewModelScope.launch`
+- Using `MutableStateFlow` with mutable collections — always use immutable copies: `_state.update { it.copy(list = it.list + newItem) }`
+- Catching `CancellationException` — let it propagate for proper cancellation
+- Using `flowOn(Dispatchers.Main)` to collect — collection dispatcher is the caller's dispatcher
+- Creating `Flow` in `@Composable` without `remember` — recreates the flow every recomposition
+
+## References
+
+See skill: `compose-multiplatform-patterns` for UI consumption of Flows.
+See skill: `android-clean-architecture` for where coroutines fit in layers.