v1.2.1

Memento v1.2.1 — Enterprise DB Self-Healing

Makes Memento resilient to the recurring binary-corruption class of failures (bytes rewritten through a text decode) instead of crashing with a cryptic database disk image is malformed.

• New memento/db_guard.py: detects SQLite corruption (PRAGMA integrity_check), backs the corrupted file up to a timestamped .corrupted-<ts> copy (db + -wal/-shm), and lets the next connection recreate a fresh store while preserving the original for sqlite3 "<file>" ".recover".
• Wired into provider.initialize (memory + KG DBs) and knowledge_graph._conn() so corruption is detected and self-healed on startup.
• memento doctor reports Memory/KG DB integrity and gains a --repair flag (backs up corrupted DBs for recreation on next start).
• .gitattributes marks binary assets (.so/.db/.sqlite/.whl/…) as binary so git never text-mangles them.
• Tests: tests/test_db_guard.py (6 pass); full suite green (431).