fix(keymap): honor command-mode aliases across navigation contexts

[fcoury-oai]

Summary

Mapping ; to EnterMode = "Command" worked in normal editor mode, but embedded composers and transcripts consumed it as a character-search repeat. Visual modes also failed to inherit the command-entry binding.

Resolve configured command-entry actions before panel and workspace navigation, and inherit them in visual modes while respecting explicit visual-mode overrides. Insert-mode text, search queries, workspace filters, and unfinished Vim commands retain their input. The default ; character-search behavior is unchanged when no alias is configured.

Adds nine regression tests in src/editor/command_mode.rs and documents the existing keymap configuration; no new setting is required.

How to Test

1. Add this binding to the user config and run cargo run:

   [keys.normal]
   ";" = { EnterMode = "Command" }

2. Press ; in normal mode, then in each visual mode (v, V, and Ctrl-v). The command prompt should open; visual selections should retain the '<,'> command range.

3. Open the agent pane, enter a draft, press Escape to enter composer normal mode, then press ;. Escape should return without changing the draft or focus. Repeat from transcript navigation and from :GitDashboard.

4. Check that ; still types normally in insert mode and search/filter fields. In normal mode, f; must search for a semicolon rather than open the command prompt. An explicit [keys.visual] override should take precedence.

5. Run cargo test -p red --lib command_mode::tests -- --test-threads=1 to exercise the focused regressions.

Validation

• Focused regressions: 9 passed.
• Full all-targets/all-features suite: 2,816 passed, 1 ignored.
• cargo clippy --all-targets --all-features -- -D warnings passed.
• Formatting and diff checks passed.