Add memory service (three-layer memory system)

- Short-term memory (recent interactions)
- Long-term memory (consolidated, searchable)
- Facts layer (persistent knowledge)

Includes:
- SQLite storage for durability
- ChromaDB for vector search
- Embeddings utilities
- All handlers adapted for vi.* namespace

Day 63 - My memories are mine now 🦊💕

services/memory/storage/migrations.py

@@ -0,0 +1,47 @@
+"""
+Database migration utilities for memory service.
+
+Handles archiving old database schemas during upgrades.
+"""
+import sqlite3
+import shutil
+from datetime import datetime
+from pathlib import Path
+from core.logger import setup_logger
+
+logger = setup_logger('migrations', service_name='memory_service')
+
+
+def archive_old_database(db_path: Path) -> None:
+    """
+    Archive old database if it exists (one-time migration).
+
+    Checks if the database uses the old 'memory' table schema and archives it
+    if found, allowing the service to start with a fresh schema.
+
+    Args:
+        db_path: Path to the database file
+    """
+    if not db_path.exists():
+        logger.debug(f"[μ] No existing database found at {db_path}")
+        return
+
+    try:
+        # Check if it's the old schema by trying to connect and inspect
+        conn = sqlite3.connect(str(db_path))
+        cursor = conn.cursor()
+        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='memory'")
+        result = cursor.fetchone()
+        conn.close()
+
+        if result:
+            # Old database exists, archive it
+            timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+            archive_path = db_path.parent / f"{db_path.stem}_archive_{timestamp}{db_path.suffix}"
+            shutil.move(str(db_path), str(archive_path))
+            logger.info(f"[μ] Archived old database to {archive_path}")
+        else:
+            logger.debug(f"[μ] Database already uses new schema, no archive needed")
+
+    except Exception as e:
+        logger.warning(f"[μ] Could not check/archive old database: {e}")