feat(memory): implement MCP tools for agent memory operations (#96)

Add MCP-compatible tools that expose memory operations to agents:

Tools implemented:
- remember: Store data in working, episodic, semantic, or procedural memory
- recall: Retrieve memories by query across multiple memory types
- forget: Delete specific keys or bulk delete by pattern
- reflect: Analyze patterns in recent episodes (success/failure factors)
- get_memory_stats: Return usage statistics and breakdowns
- search_procedures: Find procedures matching trigger patterns
- record_outcome: Record task outcomes and update procedure success rates

Key components:
- tools.py: Pydantic schemas for tool argument validation with comprehensive
  field constraints (importance 0-1, TTL limits, limit ranges)
- service.py: MemoryToolService coordinating memory type operations with
  proper scoping via ToolContext (project_id, agent_instance_id, session_id)
- Lazy initialization of memory services (WorkingMemory, EpisodicMemory,
  SemanticMemory, ProceduralMemory)

Test coverage:
- 60 tests covering tool definitions, argument validation, and service
  execution paths
- Mock-based tests for all memory type interactions

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/services/memory/mcp/__init__.py

@@ -0,0 +1,40 @@
+# app/services/memory/mcp/__init__.py
+"""
+MCP Tools for Agent Memory System.
+
+Exposes memory operations as MCP-compatible tools that agents can invoke:
+- remember: Store data in memory
+- recall: Retrieve from memory
+- forget: Remove from memory
+- reflect: Analyze patterns
+- get_memory_stats: Usage statistics
+- search_procedures: Find relevant procedures
+- record_outcome: Record task success/failure
+"""
+
+from .service import MemoryToolService, get_memory_tool_service
+from .tools import (
+    MEMORY_TOOL_DEFINITIONS,
+    ForgetArgs,
+    GetMemoryStatsArgs,
+    MemoryToolDefinition,
+    RecallArgs,
+    RecordOutcomeArgs,
+    ReflectArgs,
+    RememberArgs,
+    SearchProceduresArgs,
+)
+
+__all__ = [
+    "MEMORY_TOOL_DEFINITIONS",
+    "ForgetArgs",
+    "GetMemoryStatsArgs",
+    "MemoryToolDefinition",
+    "MemoryToolService",
+    "RecallArgs",
+    "RecordOutcomeArgs",
+    "ReflectArgs",
+    "RememberArgs",
+    "SearchProceduresArgs",
+    "get_memory_tool_service",
+]