feat(embedding,vision): candle embeddings with offline fallback, on-demand clipboard vision capture, and concurrency audit

README.md

@@ -48,6 +48,15 @@ The server consolidates granular single-purpose tools into 12 concise, action-or
 
 ## Key Features & Capabilities
 
+### 📜 VCS-Agnostic Code Change Ledger & Recent Deltas (`/api/ledger` & `memory://session/delta`)
+Maintains an audit ledger of all file modifications, commit hashes / SVN revisions (`vcs_revision`), repository branches, upstream URLs, and AI change summaries with deterministic length bounds. Fully agnostic across Git, Subversion (SVN), and Mercurial (Hg). Exposed via the Brain Monitor Web UI (`/api/ledger`) and accessible as a passive context resource (`memory://session/delta`).
+
+### 💻 Terminal & Process Telemetry (`/terminal/history`)
+Tracks active shell instances (PowerShell, Bash, Nushell, Zsh), command history, working directories, and exit codes in real time. Enables LLMs and the Brain Monitor UI to maintain total visibility over terminal execution contexts.
+
+### 📋 Enriched Task Board, ADRs & Technical Debt Backlog
+Supports structured priorities (`low`, `medium`, `high`, `urgent`), assigned subagent roles, automated verification commands, architectural decision alternatives and consequences, and granular technical debt tracking (line ranges, workarounds, effort estimates).
+
 ### 🕸️ Multi-Hop Subgraph Expansion (`get_subgraph`)
 Performs a Breadth-First Search (BFS) around a target root entity node up to a specified depth ($N$ hops), returning all connected sub-entities and relationships in a single call.
 
@@ -81,11 +90,20 @@ Records structured diagnostic hypotheses, test evidence, and verification status
 Computes structured diffs of pinned files and active task IDs between two saved context workspaces.
 
 ### 🔒 Resilient Storage & Serde Parameter Tolerances
-* **Atomic Store Write Locks**: Retains write guards during both in-memory updates and `redb` database serialization to eliminate lock-release TOCTOU race conditions.
-* **Database Quarantine Protection**: Automatically flags corrupted database keys during deserialization (`is_corrupted = true`) to prevent corrupt states from being overwritten with empty defaults on subsequent writes.
-* **Serde Relation Parameter Aliases**: `create_relations` accepts flexible aliases (`source` / `target` / `relationType` / `type`) so LLMs never encounter parameter validation errors.
+* **Explicit Fail-Fast Persistence Safety**: Replaced unsafe silent fallback to temporary databases (`/tmp/mcp_store_fallback_*`) with an explicit open retry and fail-fast panic unless `MCP_ALLOW_TMP_FALLBACK=1` is explicitly set, preventing silent data loss.
+* **Store Write Lock Minimization**: Releases write lock immediately following in-memory mutation, serializing JSON payloads under read locks to allow non-blocking concurrent readers.
+* **Two-Phase Graph Condensation**: Employs a non-destructive 2-phase commit in `condense_graph_worker` (reading without clearing, inserting into the knowledge graph, and only pruning summarized records by timestamp/content upon verified success).
+* **Redb Transient Lock Backoff**: Added exponential backoff retry loop (3 attempts, 150ms delay) on Redb table lock acquisition to gracefully handle concurrent access contention.
+* **Offloaded Background Index Rebuilds**: Heavy graph cloning and Tantivy re-indexing in `rebuild_index` are offloaded to `tokio::task::spawn_blocking` to prevent starving Tokio async worker pools.
+* **Watch-Based Non-Destructive Shutdown**: Server cancellation signals utilize `tokio::sync::watch` rather than `mpsc` to allow multi-consumer broadcast notifications.
+* **Async Mutex Deadlock Elimination**: Converted shared state and Neovim connection locks (`shutdown_tx`, `NVIM_CONN`, `ACTIVE_SOCKET`, `HEADLESS_PROC`) to `tokio::sync::Mutex` to prevent worker thread pool starvation across `.await` points.
+* **Telemetry Session Deduplication & Channel Pruning**: Added `LAST_SESSION` in-memory state deduplication for UDP telemetry writes (eliminating disk I/O thrashing) and distinguished WebSocket `TrySendError::Full` backpressure vs `TrySendError::Closed` client pruning.
+* **Graph Adjacency Indexing**: Leverages `KnowledgeGraph::build_adjacency_map` to build $O(1)$ lookup adjacency lists for fast BFS shortest path graph queries.
+* **Serde Parameter & Enum Ergonomics**: Consolidated tools support flexible aliases (`source`/`from`, `target`/`to`, `relationType`/`relation_type`, `parent_id`/`parentId`, `camelCase`/`PascalCase`/`snake_case`) so LLM tool invocations never fail due to parameter discrepancies.
+* **Embedding Input Safeguards**: `generate_embedding_async` returns explicit errors for empty string inputs instead of 0-length fallback vectors, guaranteeing vector dimension compatibility in `cosine_similarity`.
+* **Path Traversal Security Guards**: Enforces path canonicalization (`validate_safe_path`) to reject parent relative directory traversal (`..`) across process and file log endpoints.
+* **Proactive Watcher Memory Eviction**: Caps file watcher `last_processed` map size at 1,000 items and purges items older than 10 minutes to prevent long-running memory leaks.
 * **Pre-cached Embedding Search**: Reuses pre-computed snippet embeddings (`snippet.embedding`), bypassing ONNX inference latency during in-memory semantic searches.
-
 ### 📡 Real-time WebSocket Memory Sync (`ws://127.0.0.1:3000/ws`)
 Broadcasting event pipeline streams real-time graph, task, and activity mutations directly to the Brain Monitor UI.
 
@@ -160,13 +178,19 @@ To view the dashboard, open your browser at:
 * **Kanban Board:** Track active Tasks and trigger status transitions directly from the browser.
 * **Clipboard Inspector:** Review OS-level clipboard image captures via `/api/clipboard/capture`.
 * **Live WebSocket Telemetry:** Real-time UI updates triggered by server state changes.
+* **Code Change Ledger:** Chronological audit trail of all code edits, commits, and summaries.
 
 ---
 
 ## High-Performance Concurrency & Resilience Guarantees
 
+* **Atomic Store Write Lock Minimization**: `Store::modify` and `Store::modify_async` release write lock guards immediately after applying state mutations, performing JSON serialization under read guards to prevent blocking concurrent readers during state serialization.
+* **Async Commit Index Reader Auto-Reload**: `MemoryIndex::commit()` automatically reloads index searchers upon background commit completion, eliminating search latency and stale reader windows.
 * **Async Channel Backpressure (`push_async`)**: `Store::modify_async` uses `DbWriteQueue::push_async` with `tx.send(task).await` backpressure to guarantee database write persistence under heavy async write loads without dropping write transactions.
 * **Atomic Search Index Swaps**: `MemoryState::rebuild_index` constructs and populates a new `MemoryIndex` instance in isolation before performing an atomic pointer swap (`*self.search_index.write().await = new_idx`), eliminating transient empty search result windows.
-* **SIMD-Friendly Single-Pass Cosine Similarity**: `cosine_similarity` calculates dot product and Euclidean norm squares in a single linear pass over float vectors, enabling SIMD compiler auto-vectorization.
+* **Dynamic Character Micro-Batching**: `generate_embeddings_async` dynamically batches text payloads up to a 16,000 character budget inside `spawn_blocking`, eliminating heap spikes during high-volume vector indexing while keeping SIMD pipelines saturated.
+* **Bounded Telemetry Detail Records**: Activity and terminal telemetry buffers enforce a 4,000 character truncation ceiling on log details (`ActivityRecord`, `TerminalHistory`) to prevent unbounded RAM growth under heavy RPC traffic.
+* **Zero-Allocation Stream Formatting**: Graph condensation loops (`condense_graph_worker`) use `std::fmt::Write` string stream buffers to format subgraphs without allocating temporary string intermediates.
+* **SIMD-Friendly Single-Pass Cosine Similarity**: `cosine_similarity` calculates dot product and Euclidean norm squares in a single iterator fold pass over float vectors, enabling SIMD compiler auto-vectorization.
 * **Safe Stream Decoding on Log Tails**: Log tail operations (`get_recent_logs`) read raw bytes and decode using lossy UTF-8 conversion (`String::from_utf8_lossy`) to ensure resilience when seeking across multi-byte UTF-8 boundaries.
 * **Serde Parameter & Enum Tolerance**: All action enums (`StickyNoteAction`, `SnippetSearchMode`, `Relation`) support case-insensitive variants and field aliases (`source`/`from`, `target`/`to`, `relationType`/`relation_type`) to ensure seamless execution when LLMs pass varied string formatting.