fix(bridge): split NotificationCache out of Translator lock

CHANGELOG.md

@@ -11,11 +11,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - **Stale document tracker on external file changes** — `DocumentTracker::ensure_open` now stats the file on every call and resyncs the LSP server via a single full-replacement `textDocument/didChange` when the on-disk content changed. Previously a file was only ever read once per session, so external edits (git checkout/stash, formatters, the MCP host's own Edit/Write tools) went unnoticed by mcpls and produced stale hover/diagnostics/completion results until the process restarted. (#102)
 - **CodeQL fork PR checkout** — `actions/checkout@v7` refuses to check out a fork PR's head SHA in `pull_request_target` workflows unless explicitly opted in; set `allow-unsafe-pr-checkout: true` on the CodeQL workflow's checkout step, which was failing every fork-originated PR since the checkout v6 → v7 bump. Safe here because the job carries no secrets and permissions are scoped to `security-events: write` + `contents: read` only.
+- **Notification loss and cached-read stalls under translator-lock contention** — `NotificationCache` is now held behind its own `Arc<Mutex<NotificationCache>>`, independent of `Arc<Mutex<Translator>>`, and workspace-root path validation for cache-only reads uses a lock-free `Arc<[PathBuf]>` snapshot instead of locking the translator. Previously, `diagnostics_pump` wrote into the cache through the translator lock: while that lock was held elsewhere for the duration of a slow `textDocument/diagnostic` round-trip, incoming `publishDiagnostics`/log/message notifications were silently dropped (the LSP transport forwards them via a non-blocking `try_send`), and `get_cached_diagnostics`/`read_resource`/`subscribe` — which only ever needed a cached read or a path check — queued behind that same round-trip for as long as it took to complete. (#104)
+- **`get_cached_diagnostics` still held the cache lock across `canonicalize()` and result mapping** — the `Translator::handle_cached_diagnostics` split above narrowed but didn't fully close the same lock-contention class: path validation (a filesystem `canonicalize()` syscall) and the cached-diagnostics-to-MCP-shape mapping still ran while holding the `notification_cache` mutex that `diagnostics_pump` also needs. Split into `Translator::cached_diagnostics_uri` (path validation, no lock involved) and `Translator::diagnostics_from_cache_entry` (pure mapping over an already-cloned entry, no lock involved); `get_cached_diagnostics` now holds the cache lock only for the `get_diagnostics(&uri).cloned()` lookup itself. (#104)
+- **`read_resource` used the raw, non-canonicalized path to build its diagnostics-cache URI** — `validate_path_against_roots` returns the canonicalized path but the result was discarded, so `read_resource` looked up the cache under the client's original (possibly symlinked or `..`-containing) path instead of the canonical form `diagnostics_pump` actually stores diagnostics under, causing spurious cache misses for otherwise-valid, tracked files. Fixed to build the URI from the validated/canonical path, matching `get_cached_diagnostics`. (#104)
 
 ### Changed
 
 - **`DocumentState` API** — Breaking change: `DocumentState` gains a `disk: Option<DiskSync>` field tracking the filesystem snapshot behind the resync mechanism above; existing struct-literal construction must add this field. Acceptable pre-1.0. (#102)
 - **`rmcp` 2.2.0** — Breaking change upstream: bump `rmcp` from 1.8.0 to 2.2.0 to align with the MCP 2025-11-25 spec. `rmcp::model::RawResource` and the `Annotated<RawResource>` wrapper were merged into a single flat `rmcp::model::Resource` struct; `McplsServer::list_resources` updated accordingly.
+- **`McplsServer::new` / `HandlerContext::new` signatures** — Breaking change: both now take an additional `Arc<Mutex<NotificationCache>>` and an `Arc<[PathBuf]>` workspace-roots snapshot, alongside the existing translator and subscriptions. `Translator::handle_cached_diagnostics` was removed and replaced by `Translator::cached_diagnostics_uri(workspace_roots, file_path) -> Result<String>` and `Translator::diagnostics_from_cache_entry(Option<&DiagnosticInfo>) -> DiagnosticsResult`, so callers control exactly how long the `NotificationCache` lock is held between the two; `Translator::handle_server_logs`/`handle_server_messages` became associated functions taking `&NotificationCache` directly, since neither needed translator state. Acceptable pre-1.0. (#104)
 
 ### Fixed
 

crates/mcpls-core/src/bridge/mod.rs

@@ -15,6 +15,7 @@ pub use notifications::{
 };
 pub use resources::ResourceSubscriptions;
 pub use state::{DocumentState, DocumentTracker, path_to_uri, uri_to_path};
+pub(crate) use translator::validate_path_against_roots;
 pub use translator::{
     Completion, CompletionsResult, DefinitionResult, Diagnostic, DiagnosticSeverity,
     DiagnosticsResult, DocumentChanges, DocumentSymbolsResult, FormatDocumentResult, HoverResult,