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)

src/index.ts

@@ -37,6 +37,16 @@ import {
   componentGraph,
 } from './tools/impact.js';
 import { memoryAdd, memorySearch, memoryList, memoryContext } from './tools/memories.js';
+import {
+  sessionStart,
+  sessionUpdate,
+  sessionEnd,
+  sessionList,
+  sessionSearch,
+  sessionContext,
+  buildRecord,
+  sessionCommitLink,
+} from './tools/sessions.js';
 
 // Create MCP server
 const server = new Server(
@@ -329,6 +339,8 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
           content: a.content,
           context: a.context,
           project: a.project,
+          session_id: a.session_id,
+          task_id: a.task_id,
         });
         break;
       case 'memory_search':
@@ -350,6 +362,69 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
         result = await memoryContext(a.project, a.task_description);
         break;
 
+      // Sessions
+      case 'session_start':
+        result = await sessionStart({
+          session_id: a.session_id,
+          project: a.project,
+          working_directory: a.working_directory,
+          git_branch: a.git_branch,
+          initial_prompt: a.initial_prompt,
+        });
+        break;
+      case 'session_update':
+        result = await sessionUpdate({
+          session_id: a.session_id,
+          message_count: a.message_count,
+          token_count: a.token_count,
+          tools_used: a.tools_used,
+        });
+        break;
+      case 'session_end':
+        result = await sessionEnd({
+          session_id: a.session_id,
+          summary: a.summary,
+          status: a.status,
+        });
+        break;
+      case 'session_list':
+        result = await sessionList({
+          project: a.project,
+          status: a.status,
+          since: a.since,
+          limit: a.limit,
+        });
+        break;
+      case 'session_search':
+        result = await sessionSearch({
+          query: a.query,
+          project: a.project,
+          limit: a.limit,
+        });
+        break;
+      case 'session_context':
+        result = await sessionContext(a.session_id);
+        break;
+      case 'build_record':
+        result = await buildRecord(
+          a.session_id,
+          a.version_id,
+          a.build_number,
+          a.git_commit_sha,
+          a.status,
+          a.started_at
+        );
+        break;
+      case 'session_commit_link':
+        result = await sessionCommitLink(
+          a.session_id,
+          a.commit_sha,
+          a.repo,
+          a.commit_message,
+          a.committed_at
+        );
+        break;
+
       default:
         throw new Error(`Unknown tool: ${name}`);
     }