fix(sqlite): invalidate engine cache on snapshot restore

[chaliy]

Motivation

• A session-scoped SQLite engine cache allowed cached connections to survive Bash::restore_snapshot(), enabling stale DB state to be read or flushed back into a restored VFS.
• Restore must preserve the snapshot/VFS boundary so builtin caches cannot leak previous-session data or corrupt restored files.

Description

• Add a builtin hook reset_session_state() (default no-op) to clear hidden per-instance state and wire it into the interpreter as reset_builtin_session_state() called from restore_snapshot after VFS restoration.
• Implement reset_session_state() for the Sqlite builtin to clear the per-database engine_cache.
• Harden the VFS-backed SQLite path by opening each Vfs engine with a unique Turso-internal path and a BashkitVfsIO alias that maps the Turso path back to the caller VFS path, preventing Turso's process-level registry from resurrecting stale engines.
• Expose cached bytes from BashkitVfsIO and extend SqliteEngine::snapshot_bytes() to consult VFS-backed buffers so cache invalidation checks can compare current VFS bytes.
• Add integration tests that restore a clean snapshot into an existing Bash and assert the SQLite cache is invalidated for both Memory and Vfs backends, and update specs/sqlite-builtin.md to document the new guarantee.

Testing

• Ran cargo fmt --all -- --check and it succeeded.
• Ran the targeted integration tests via cargo test --features sqlite -p bashkit --test integration snapshot_restore_into_existing_bash_clears_sqlite_cache -- --nocapture and they passed.
• Ran the full SQLite integration suite via cargo test --features sqlite -p bashkit --test integration sqlite_integration_tests -- --nocapture and all tests passed.
• Ran cargo clippy for the SQLite feature and it passed with zero warnings treated as errors.

---

Codex Task

[cloudflare-workers-and-pages]

Deploying with    Cloudflare Workers

The latest updates on your project. Learn more about integrating Git with Workers.

Status	Name	Latest Commit	Preview URL	Updated (UTC)
✅ Deployment successful! View logs	bashkit	20e2e90	Commit Preview URL	Jun 02 2026, 09:32 AM