Add a Tauri command

Follow this in order. The rules it protects are in CLAUDE.md and docs/development/rust-conventions.md. A command validates input, calls one service or db:: function, and maps the error to String.

Do not copy a file listed under docs/development/module-map.md#seam-debt. Those files still open git2 repositories. tests/agent-infra/git2-ownership.test.mjs pins that list.

1. Put the command in src-tauri/src/commands/. Blocking work (SQLite, std::fs, preferences::load, preferences::save, git, network) is a plain sync *_blocking core plus a #[command] async fn that calls run_blocking from src-tauri/src/blocking.rs. A fast in-memory command may stay a sync #[command] fn.
2. Register it in tauri::generate_handler! in src-tauri/src/lib.rs. A missing entry fails at runtime with "command not found". A command that only tests or crash diagnosis need is dev-only: gate the entry with #[cfg(any(debug_assertions, feature = "dev-tools"))] so the release window does not answer the name (issue #2153), and add it to the expected list in tests/unit/ipc-contract.test.ts.
3. If it calls a Tauri core window or app API, grant that capability in src-tauri/capabilities/default.json. A missing grant fails silently in a production build.
4. Wire structs derive TS with #[ts(export, export_to = "Name.ts")]. Annotate i64, u64, and usize with #[ts(as = "i32")], and Option<i64> with #[ts(as = "Option<i32>")]. A list of ids on the wire is Vec<i32>. Run cargo test with working directory src-tauri/ so src/types/generated updates. Commit the generated files. Never hand-edit them, and never declare a TypeScript interface for the same struct.
5. Put the desktop wrapper on the facet that already owns the area: src/lib/tauri/provider.ts, src/lib/tauri/circuitBlueprint.ts, src/lib/tauri/circuitEvidence.ts, src/lib/tauri/history.ts, or src/lib/tauri/stateRecovery.ts. Otherwise add it to src/lib/tauri.ts. Every wrapper calls _invoke from src/lib/tauri/_invoke.ts. Do not call invoke anywhere else.
6. A mobile route under src-tauri/src/http/routes awaits the async command wrapper, or calls run_blocking itself. It must not call the *_blocking core on the async worker.
7. Cover malformed input, a missing dependency, and acknowledged success at that command or route. The guards are tests/unit/ipc-contract.test.ts, tests/unit/tauri-ipc-seam.test.ts, and tests/unit/async-command-blocking.test.ts.
8. Document the user-visible behavior or the developer/API contract. A security or lifecycle decision goes in docs/adr/.

From the worktree root, with NODE_ENV=test:

npx vitest run tests/unit/ipc-contract.test.ts tests/unit/tauri-ipc-seam.test.ts tests/unit/async-command-blocking.test.ts --pool=threads

Rust behaviour: from src-tauri/, cargo test --lib <module>. Build dist/mobile first (npm run build:mobile) when that directory is missing.