ci / rust (push) Successful in 15m8s
`TuiConfig::load(&TuiSection)` builds the runtime config:
1. Apply shipped default Normal-mode bindings (cover every v1 action).
2. Insert mode binds the leader → `LeaveInsert` (built from the leader spec
so rebinding leader moves the Insert escape automatically).
3. Apply user overrides from `[tui.keymap.normal]` / `[tui.keymap.insert]`
over the defaults, with the same validation path — bad TOML entries
surface as `BadKeymap { mode, input, action, source }`.
Also adjusts the existing `MaestroConfigFile` round-trip test to include the
new `tui` field.
8 new unit tests passing (49 total for tui + config).