Add session management MCP tools (Phase 3)

Implemented 8 new session management tools:
- session_start: Initialize session with metadata tracking
- session_update: Update session metrics during execution
- session_end: Close session with summary and embedding
- session_list: List sessions with filtering
- session_search: Semantic search across sessions
- session_context: Get complete session context (tasks, commits, builds, memories)
- build_record: Link builds to sessions and versions
- session_commit_link: Link commits to sessions

Enhanced existing tools:
- memory_add: Added session_id and task_id parameters
- Updated all memory queries to use 'memories' table (renamed from session_memories)

Implementation:
- Created src/tools/sessions.ts with all session operations
- Updated src/tools/memories.ts for new schema
- Added 8 session tool definitions to src/tools/index.ts
- Registered all session tools in src/index.ts switch statement
- TypeScript compilation successful

Related: CF-167 (Fix shared session-summary.md file conflict)

README.md

@@ -4,9 +4,9 @@ Exposes task management tools via Model Context Protocol. Uses PostgreSQL with p
 
 ## Requirements
 
-- SSH tunnel to docker-host: `ssh -L 5432:localhost:5432 docker-host -N &`
-- PostgreSQL with pgvector on docker-host (CI stack `postgres` container)
-- CI postgres must be running: `ssh docker-host "cd /opt/docker/ci && docker compose up -d postgres"`
+- SSH tunnel to services: `ssh -L 5432:localhost:5432 services -N &`
+- PostgreSQL with pgvector on services (CI stack `postgres` container)
+- CI postgres must be running: `ssh services "cd /opt/docker/ci && docker compose up -d postgres"`
 
 ## Configuration