feat: pet chat window replaces the Sagi panel; Windows pane attach no longer crashes the server

- Sagi: clicking the pet opens its chat window directly (PetChat + SagiInfo
  status strip, Needs you, Mute / Clear alerts); SagiPanel removed.
- Chat view answers Claude's unnumbered folder-trust prompt (parseBareMenu).
- pty-attach: resize/write after a Windows attach exited, and node-pty's pipe
  errors, no longer throw out of the WebSocket handler.
- restart-helper: the server started by an update logs to
  data/agenthub-server.log instead of discarding its output.

docs/API.md

@@ -2954,7 +2954,7 @@ POST   /api/pets/featured/:id         Download a FEATURED pet from codex-pets.ne
 DELETE /api/pets/:id                  Delete a pet (its folder under the data dir)
 ```
 
-The mascot (Sagi) can wear a pet: right-click it for **Hide pet**, **Size** (48–250 px), **Choose pet** (Sagi, the featured pets, your own — deletable), **Upload your own…**, **Import .codex-pet bundle…**, **Find more on codex-pets.net** and **Pet settings…**, which opens the pet block of **Settings → Appearance** (`/settings/appearance#pet`, `client/src/components/settings/PetSettings.tsx`; the old `/settings/pet` redirects there): show/hide, speech bubbles, size with a live preview, and the same choose / download / upload / import / delete as a grid. The menu and the page share `components/Sagi/usePets.ts`. Which pet is worn (with its display name, which the mascot goes by) and its size are viewer preferences in `localStorage` (`agenthub.pet`, `agenthub.pet.size`); a name the user types by clicking it in the mascot's panel is `agenthub.pet.names` (`{ [petId]: name }`, empty = the pet's own); the pets live on the server, one folder each under `<data dir>/pets/<id>/` with a `meta.json` AgentHub writes.
+The mascot (Sagi) can wear a pet: right-click it for **Hide pet**, **Size** (48–250 px), **Choose pet** (Sagi, the featured pets, your own — deletable), **Upload your own…**, **Import .codex-pet bundle…**, **Find more on codex-pets.net** and **Pet settings…**, which opens the pet block of **Settings → Appearance** (`/settings/appearance#pet`, `client/src/components/settings/PetSettings.tsx`; the old `/settings/pet` redirects there): show/hide, speech bubbles, size with a live preview, and the same choose / download / upload / import / delete as a grid. The menu and the page share `components/Sagi/usePets.ts`. Which pet is worn (with its display name, which the mascot goes by) and its size are viewer preferences in `localStorage` (`agenthub.pet`, `agenthub.pet.size`); a name the user types by clicking it in the mascot's chat window header is `agenthub.pet.names` (`{ [petId]: name }`, empty = the pet's own); the pets live on the server, one folder each under `<data dir>/pets/<id>/` with a `meta.json` AgentHub writes.
 
 A **Codex pet** is the `.codex-pet.zip` format Codex Desktop uses (the bundles shared on codex-pets.net and in `mileson/codex-pets`): `pet.json` (`id`, `displayName`, `description`, `spritesheetPath`) and `spritesheet.webp`, a 1536×1872 atlas of 8 columns × 9 rows of 192×208 frames — idle, run right, run left, waving, jumping, failed, waiting, running, review, with 6/8/8/4/5/8/6/6/6 frames — or a v2 atlas (`spriteVersionNumber: 2`, 1536×2288, 11 rows) whose rows 9–10 add 16 gaze poses, 22.5° apart clockwise from straight up. The mascot plays the row of its mood (an agent working → running, waiting for you → waiting, an error → failed, a finished turn → jumping, a live session at rest → review, idle/asleep → idle), and on an event it plays a moment over the mood (a new session → waving, a finish or a pat → jumping, a new subagent → review, a session waiting on you → waiting, an error → failed); dragged it runs left or right with the drag (and along the glide to its edge), hovered it waves, and a v2 pet at idle turns toward the pointer (back to idle 2 s after the pointer rests). Frames play at Codex's own timings (`codex-rs/tui/src/pets/model.rs`: e.g. running 120 ms a frame, its last 220 ms); idle plays at the drawn pace (280/110/110/140/140/320 ms), a sleeping pet at Codex's 6× slower one. Waving, jumping, failed and review are moments — they play three times and settle into idle; running, waiting and the run rows loop. Only the two files are read, at the archive root or one folder deep; an entry's size is checked from the zip's directory before it is inflated; the sheet must be a WebP of exactly one of those sizes (`400 EBADPET` otherwise). An uploaded image is shown still and bobs; SVG is refused because an SVG served from the dashboard's origin runs script.