Let Kaku users launch sessions from their chosen terminal (#1954) (#1983)

Kaku is a WezTerm-derived macOS terminal, so reusing the existing WezTerm-compatible launch path keeps the change small while making it selectable in settings and session resume flows.

Constraint: Kaku support should stay macOS-only and avoid introducing a separate launcher model
Rejected: Treat Kaku as a silent WezTerm fallback | users could not explicitly choose it in settings
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep Kaku on the shared WezTerm-compatible launch path unless upstream drops the start-compatible CLI
Tested: pnpm typecheck; pnpm format:check; cargo check --manifest-path src-tauri/Cargo.toml; cargo fmt --manifest-path src-tauri/Cargo.toml --check; cargo test --manifest-path src-tauri/Cargo.toml --lib session_manager::terminal::tests
Not-tested: End-to-end launch against a locally installed Kaku.app
Related: #1954

src/components/settings/TerminalSettings.tsx

@@ -16,6 +16,7 @@ const MACOS_TERMINALS = [
   { value: "kitty", labelKey: "settings.terminal.options.macos.kitty" },
   { value: "ghostty", labelKey: "settings.terminal.options.macos.ghostty" },
   { value: "wezterm", labelKey: "settings.terminal.options.macos.wezterm" },
+  { value: "kaku", labelKey: "settings.terminal.options.macos.kaku" },
 ] as const;
 
 const WINDOWS_TERMINALS = [