The kon-mcp stdio server is documented as "read-only, no auth, local-only"
but until now opened the SQLite store via `kon_storage::init`, which returns
a writable pool and runs migrations. Read-only-ness was enforced only by the
exposed tool surface (list_transcripts, get_transcript, search_transcripts,
list_tasks); a future bug or a malformed dispatch could escape into a write
against the user's primary database.
Add `kon_storage::init_readonly` that opens with `SqliteConnectOptions
::read_only(true)` and `create_if_missing(false)`, no migrations. The
constraint is now structural — SQLite rejects writes at the connection
level regardless of which handler runs.
- New `init_readonly(path)` in crates/storage/src/database.rs.
- Re-exported from kon_storage.
- crates/mcp/src/main.rs switched over and updated startup banner.
- Two tests: writes fail on the read-only pool, reads succeed; opening a
non-existent DB returns an error instead of silently creating one.
https://claude.ai/code/session_0189xUb6ie6t9qHkzatGZ9Rb
90f4d9b0fb