v0.2.0 — Phase 1 + community oasis

v0.2.0 — Phase 1 (SQLite + crash-resume)

• SqliteStore with WAL, runs / effects / journal tables
• Runtime::resume verifies hash chain then continues
• Crash-resume + HITL reopen tests
• CLI --db for durable runs
• Docs: architecture, vision (oasis), community health files, CI