fix(mise-init): unblock the bootstrap agent + surface live agent output

The mise-init agent wedged on launch and the UI reported it green. Three
distinct problems, fixed together:

1. Onboarding wedge (the proximate bug). A freshly-installed claude opens
   interactive setup — theme picker, then a folder-trust prompt — before
   the REPL. A detached tmux agent has no one to answer it, so it sat on
   the theme picker forever while agents.status said 'working'. New
   control.claude_config.ensure_onboarded() marks onboarding complete and
   trusts the working dir in ~/.claude.json (merge-only, so the login
   flow's oauthAccount survives); spawn() calls it before launching.

2. Config-name gate. control/mise.py only recognized `.mise.toml`, so a
   repo shipping `mise.toml` (no dot) — or config under `.config/mise/` —
   failed the [tasks.test] gate even when healthy. It now accepts the
   filenames mise itself reads and scans them all for the test task.

3. "Done" != done (the design gap). A spawned agent's real state lives in
   its tmux pane, but the socket is control-container-only, so the API
   couldn't see it. The worker now snapshots each working agent's pane
   tail (last ~40 lines) into two new agents columns (last_output,
   output_at, migration 0007) on its existing poll loop; the API
   serializes them and AgentsSection renders a live-output <pre> under
   each running agent. A wedged agent now shows the theme picker instead
   of a misleading green badge.

Tests: home-dir writes are isolated to tmp in conftest; added coverage for
claude_config seeding/merge, the mise filename set, the worker capture
(including dead-session skip), and the API serialization.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BxKY28XKCM6o4ag3nmaVsZ

frontend/lib/api.ts

@@ -30,6 +30,10 @@ export interface Agent {
   working_dir: string;
   status: string;
   role?: string | null;
+  /* Latest tmux pane-tail snapshot from the worker, so the UI can show what a running
+   * agent is actually doing (and expose one wedged on an interactive prompt). */
+  last_output?: string | null;
+  output_at?: string | null;
   created_at: string;
 }