refactor(tui): use command IDs for v2 keybinds

[kommander]

Summary

• define V2 keybinds directly by canonical command ID while keeping the legacy plugin shim on V1
• migrate fresh and existing CLI config keybinds with canonical precedence, duplicate-value preservation, JSONC preservation, and serialized config access
• wire app, composer, diff viewer, dialog, and mini commands through resolved V2 bindings
• preserve current V2 defaults, including agent cycling, message navigation, MCP toggle, and service restart naming
• add runtime coverage for rebinding, disabling, migration, and mini config handoff

Testing

• bun turbo typecheck --concurrency=3
• TUI suite: 502 passed, 5 skipped
• CLI suite: 166 passed with inherited OTLP exporter variables unset