Merge branch 'master' into worktree/dsh-arg-parser

Integrate the Commander adapter with master's headless rework (dsh -p now boots
through AppCLIEntry — the same cordis.yml composition as dsh web, web-observable
while it runs — via toFetchHandler(ctx.apiProxy)).

- headless.ts: keep master's AppCLIEntry-based body but take the adapter's
  pre-parsed `task` (drop the re-added parseArgs). Old startHost path and the
  now-deleted packages/host/runtime dependency are gone.
- remove the stale packages/host/runtime dir left on disk by master's deletion
  (mirrors the earlier packages/ui/acp cleanup).

packages/ui/tui/tests/tui.spec.ts

@@ -3484,8 +3484,7 @@ describe('terminal mounting', () => {
     await tick()
     expect(result.terminal.output.length).toBe(beforeSameScheme)
 
-    // Simulate the terminal responding with a light color scheme report
-    // (ESC [?997;2n = light, ESC [?997;1n = dark).
+    // ESC [?997;2n reports light; ESC [?997;1n reports dark.
     result.terminal.send('\x1b[?997;2n')
     await tick()
     await tick()
@@ -3497,11 +3496,9 @@ describe('terminal mounting', () => {
     // uses ANSI 90 for the same header text.
     expect(result.terminal.output).toContain('\x1b[90mdeepseek-v4-flash')
 
-    // Switch back to dark scheme.
     result.terminal.send('\x1b[?997;1n')
     await tick()
     await tick()
-    // After switching back, a new write uses SGR 2 for the header detail.
     expect(result.terminal.output).toContain('\x1b[2mdeepseek-v4-flash')
     await dispose(result)
   })