feat(pet): cleared alerts stay cleared, contextual bubbles, i18n, moments, chat window

- Fix: an errored session alerted on every update, and Clear alerts only
  dropped it in memory, so its next update (or a reload) brought the alert
  straight back. An error now alerts on the transition into error only;
  cleared sessions are remembered (agenthub.pet.dismissedErrors) and stay
  quiet until they recover and fail anew.
- Quips, greetings, notifications and Ask answers move to i18n (EN/VI);
  Ask understands Vietnamese keywords and names the sessions it counts.
- The pet goes by the worn pet's name; click it in the panel to rename
  (agenthub.pet.names, synced to the account).
- Bubbles name the session they are about, with an Open button (never a
  resume); a burst of the same event coalesces into one count.
- Moments: a new session waves, a finish hops, a subagent peeks, a wait taps,
  an error flinches — on Sagi, Codex sprites and still images. Idle fidgets,
  a once-per-session greeting, a "Needs you" list, an amber waiting dot.
- Pat (heart button, Ask, or stroking the pet) reacts on the pet itself, so
  it shows while the panel or chat is open.
- Panel drops Run Claude / Activity / Sessions / Errored.
- Ask hands off to a chat window (PetChat) on the default AI tool
  (Claude/Codex): transcript as bubbles, follow-ups and CLI menus through an
  off-screen attached terminal; no new server route.

Verified on HEAD + this diff in a clean worktree: tsc -b, the full client
suite (1334/1335; the one failure, ConversationView.follow, is flaky under
load and passes 3/3 alone) and server me-prefs.test.js.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

client/src/components/Sagi/SagiAvatar.tsx

@@ -37,12 +37,14 @@
  * ============================================================================= */
 
 import { memo, useEffect, useRef } from "react";
-import type { Mood } from "./brain";
+import type { Mood, PetMoment } from "./brain";
 
 interface SagiAvatarProps {
   mood: Mood;
   reducedMotion: boolean;
   size?: number;
+  /** A one-shot reaction (hop, wiggle, flinch…) played over the mood. */
+  moment?: PetMoment | null;
 }
 
 const MAX_PUPIL_SHIFT = 36; // px in the 1280-unit path coordinate space
@@ -88,6 +90,7 @@ export const SagiAvatar = memo(function SagiAvatar({
   mood,
   reducedMotion,
   size = 68,
+  moment = null,
 }: SagiAvatarProps) {
   const rootRef = useRef<SVGSVGElement | null>(null);
   const rafRef = useRef<number>();
@@ -148,6 +151,7 @@ export const SagiAvatar = memo(function SagiAvatar({
       ref={rootRef}
       className="sagi-avatar"
       data-mood={mood}
+      data-moment={moment ?? undefined}
       data-reduced={reducedMotion ? "1" : "0"}
       width={size}
       height={size}