refactor: apply 5-pass audit optimizations across mcp-memory codebase

README.md

@@ -80,6 +80,12 @@ Records structured diagnostic hypotheses, test evidence, and verification status
 ### 🔀 Context Workspace Diffing (`context_workspaces`)
 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.
+* **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.
 
@@ -154,3 +160,13 @@ 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.
+
+---
+
+## High-Performance Concurrency & Resilience Guarantees
+
+* **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.
+* **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.