feat(core): unify engine home under ~/.coven with in-place migration (Phase 4, Track C)

COVEN.md

@@ -27,6 +27,8 @@ are rebranded. This boundary is explicit and documented below.
 | Binary name | `src-rust/crates/cli/src/main.rs`, `src-rust/crates/cli/src/bin/coven-cave.rs` | `coven-code`; `coven-cave` alias |
 | npm package | `npm/package.json` | `@opencoven/coven-code` |
 | Data/cache dirs | `src-rust/crates/core/src/snapshot/`, `skill_discovery.rs`, `update_check.rs`, `app.rs` | `coven-code/` |
+| Engine home (standalone) | `src-rust/crates/core/src/lib.rs` (`config_home`) | `~/.coven-code/` |
+| Engine home (under coven CLI) | `src-rust/crates/core/src/lib.rs` (`config_home`) | `~/.coven/code/` — migrated in-place from `~/.coven-code/` on first launch; legacy path is symlinked to new location |
 | Env var prefix | throughout `src-rust/` | `COVEN_CODE_*` |
 | User-Agent | `src-rust/crates/tools/src/web_search.rs`, `update_check.rs` | `CovenCode/x.y` |
 | System prompt identity | `src-rust/crates/core/src/system_prompt.rs` | "You are Coven Code…" |

src-rust/crates/cli/src/main.rs

@@ -401,6 +401,11 @@ fn handle_exit_key(
 }
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
+    // Perform a best-effort, non-fatal relocation of the engine home from the
+    // legacy ~/.coven-code/ to ~/.coven/code/ when running under the unified
+    // coven CLI.  Must run before any Settings::load() or auth/config access.
+    claurst_core::home_migration::migrate_if_needed();
+
     let raw_args: Vec<String> = std::env::args().collect();
 
     // Fast-path: `coven-code upgrade [--version <v>] [--force]` — self-update.

src-rust/crates/core/src/accounts.rs

@@ -255,9 +255,7 @@ pub fn ensure_unique_profile_id(registry: &AccountRegistry, provider: &str, base
 
 /// `~/.coven-code/`.
 pub fn claurst_dir() -> PathBuf {
-    dirs::home_dir()
-        .unwrap_or_else(|| PathBuf::from("."))
-        .join(".coven-code")
+    crate::config::config_home()
 }
 
 /// `~/.coven-code/accounts/<provider>/<id>/`.

src-rust/crates/core/src/attachments.rs

@@ -93,7 +93,7 @@ pub fn get_attachments(ctx: &AttachmentContext<'_>) -> Vec<Attachment> {
 /// Returns a formatted string like:
 /// `IDE: VS Code, workspace: /path/to/project, selection: L10-L20 in foo.rs`
 pub fn get_ide_context() -> Option<String> {
-    let lockfile_dir = dirs::home_dir()?.join(".coven-code").join("ide");
+    let lockfile_dir = crate::config::config_home().join("ide");
     let entries = std::fs::read_dir(&lockfile_dir).ok()?;
 
     for entry in entries.flatten() {

src-rust/crates/core/src/auth_store.rs

@@ -30,10 +30,7 @@ pub struct AuthStore {
 impl AuthStore {
     /// Path to the auth store file.
     pub fn path() -> PathBuf {
-        let dir = dirs::home_dir()
-            .unwrap_or_else(|| PathBuf::from("."))
-            .join(".coven-code");
-        dir.join("auth.json")
+        crate::config::config_home().join("auth.json")
     }
 
     /// Load the store from disk (returns default if missing or invalid).

src-rust/crates/core/src/claudemd.rs

@@ -911,9 +911,10 @@ pub fn load_all_memory_files_with_options(
     let mut files = Vec::new();
 
     // 1. Managed: ~/.coven-code/rules/*.md
-    if let Some(home) = memory_home_dir() {
+    {
+        let config_home = crate::config::config_home();
         if options.allow_managed_rules {
-            let rules_dir = home.join(".coven-code/rules");
+            let rules_dir = config_home.join("rules");
             if let Ok(entries) = std::fs::read_dir(&rules_dir) {
                 let mut paths: Vec<PathBuf> = entries
                     .flatten()
@@ -937,7 +938,7 @@ pub fn load_all_memory_files_with_options(
 
         // 2. User: ~/.coven-code/AGENTS.md then ~/.coven-code/CLAUDE.md
         if options.allow_user_memory {
-            load_scope_files(&home.join(".coven-code"), MemoryScope::User, &mut files);
+            load_scope_files(&config_home, MemoryScope::User, &mut files);
         }
     }
 
@@ -973,16 +974,12 @@ pub fn enumerate_context_memory_files(
     let mut files: Vec<MemoryFileInfo> = Vec::new();
 
     if options.allow_user_memory {
-        if let Some(home) = dirs::home_dir() {
-            let global = home
-                .join(".coven-code")
-                .join(crate::constants::CLAUDE_MD_FILENAME);
-            if global.exists() {
-                if let Some(file) = load_memory_file(&global, MemoryScope::User)
-                    .filter(|file| memory_file_allowed_for_options(file, options))
-                {
-                    files.push(file);
-                }
+        let global = crate::config::config_home().join(crate::constants::CLAUDE_MD_FILENAME);
+        if global.exists() {
+            if let Some(file) = load_memory_file(&global, MemoryScope::User)
+                .filter(|file| memory_file_allowed_for_options(file, options))
+            {
+                files.push(file);
             }
         }
     }

src-rust/crates/core/src/context_collapse.rs

@@ -153,10 +153,7 @@ fn summarize_messages(messages: Vec<Message>, _max_tokens: u64) -> (Vec<Message>
 /// Persist collapse state to ~/.coven-code/context_collapse_state.json
 #[cfg(feature = "cached_microcompact")]
 pub fn save_collapse_state(_session_id: &str, state: &CollapseState) -> anyhow::Result<()> {
-    let path = dirs::home_dir()
-        .ok_or_else(|| anyhow::anyhow!("Could not determine home directory"))?
-        .join(".coven-code")
-        .join("context_collapse_state.json");
+    let path = crate::config::config_home().join("context_collapse_state.json");
 
     std::fs::create_dir_all(path.parent().unwrap())?;
     let json = serde_json::to_string(state)?;
@@ -167,9 +164,7 @@ pub fn save_collapse_state(_session_id: &str, state: &CollapseState) -> anyhow::
 /// Load collapse state from ~/.coven-code/context_collapse_state.json
 #[cfg(feature = "cached_microcompact")]
 pub fn load_collapse_state(_session_id: &str) -> Option<CollapseState> {
-    let path = dirs::home_dir()?
-        .join(".coven-code")
-        .join("context_collapse_state.json");
+    let path = crate::config::config_home().join("context_collapse_state.json");
 
     if !path.exists() {
         return None;

src-rust/crates/core/src/feature_flags.rs

@@ -50,7 +50,7 @@ pub struct FeatureFlagManager {
     http_client: reqwest::Client,
 }
 
-impl FeatureFlagManager {
+impl FeatureFlagManager {
     /// Create a new feature flag manager
     ///
     /// The API key is automatically fetched from the GROWTHBOOK_API_KEY environment variable.
@@ -66,12 +66,11 @@ impl FeatureFlagManager {
             cache_ttl,
             http_client: reqwest::Client::new(),
         }
-    }
+    }
 
     /// Get the cache file path (~/.coven-code/feature_flags.json)
     fn get_cache_path() -> PathBuf {
-        let home = dirs::home_dir().unwrap_or_else(|| PathBuf::from("."));
-        home.join(".coven-code").join("feature_flags.json")
+        crate::config::config_home().join("feature_flags.json")
     }
 
     /// Check if a feature flag is enabled
@@ -213,13 +212,13 @@ impl FeatureFlagManager {
         }
         debug!("Loaded {} feature flags", flags.len());
     }
-}
-
-impl Default for FeatureFlagManager {
-    fn default() -> Self {
-        Self::new()
-    }
-}
+}
+
+impl Default for FeatureFlagManager {
+    fn default() -> Self {
+        Self::new()
+    }
+}
 
 /// Response from GrowthBook API
 #[derive(Debug, Deserialize)]
@@ -228,6 +227,13 @@ struct GrowthBookApiResponse {
     pub features: Vec<FeatureFlag>,
 }
 
+/// Test accessor — exposes the private cache path for cross-module
+/// consolidation tests (Phase 4.1).
+#[cfg(test)]
+pub(crate) fn feature_flags_cache_path_for_test() -> PathBuf {
+    FeatureFlagManager::get_cache_path()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src-rust/crates/core/src/goal.rs

@@ -161,13 +161,13 @@ impl GoalStore {
     }
 
     /// Default path: `~/.coven-code/goals.sqlite`.
-    pub fn default_path() -> Option<PathBuf> {
-        dirs::home_dir().map(|h| h.join(".coven-code").join("goals.sqlite"))
+    pub fn default_path() -> PathBuf {
+        crate::config::config_home().join("goals.sqlite")
     }
 
     /// Open using the default path (best-effort; returns None on failure).
     pub fn open_default() -> Option<Self> {
-        Self::default_path().and_then(|p| Self::open(&p).ok())
+        Self::open(&Self::default_path()).ok()
     }
 
     fn now_ms() -> u64 {
@@ -697,4 +697,14 @@ mod tests {
             std::env::remove_var("COVEN_CODE_GOALS");
         }
     }
+
+    #[test]
+    fn default_path_derives_from_config_home() {
+        let path = GoalStore::default_path();
+        assert!(
+            path.starts_with(crate::config::config_home()),
+            "default_path {path:?} should start with config_home()"
+        );
+        assert_eq!(path.file_name().unwrap(), "goals.sqlite");
+    }
 }