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/__tests__/PetChat.test.ts

@@ -0,0 +1,46 @@
+/**
+ * @file PetChat.test.ts
+ * @description Unit tests for the pet chat's transcript-to-bubbles folding (`chatLines`).
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+import { describe, it, expect } from "vitest";
+import { chatLines } from "../PetChat";
+import type { TranscriptMessage } from "../../../lib/types";
+
+const msg = (m: Partial<TranscriptMessage>): TranscriptMessage =>
+  ({ type: "user", timestamp: null, content: [], ...m }) as TranscriptMessage;
+
+describe("chatLines", () => {
+  it("keeps the user's words and the assistant's prose, folding tool calls into one chip", () => {
+    const lines = chatLines([
+      msg({ type: "user", sender: "user", content: [{ type: "text", text: "hi" }] }),
+      msg({
+        type: "assistant",
+        content: [
+          { type: "thinking", text: "hmm" },
+          { type: "tool_use", name: "Read" },
+        ],
+      }),
+      msg({ type: "user", sender: "tool", content: [{ type: "tool_result", output: "x" }] }),
+      msg({
+        type: "assistant",
+        content: [
+          { type: "tool_use", name: "Read" },
+          { type: "text", text: "hello!" },
+        ],
+      }),
+    ]);
+    expect(lines.map((l) => (l.role === "tools" ? l.names : l.text))).toEqual([
+      "hi",
+      ["Read", "Read"],
+      "hello!",
+    ]);
+  });
+
+  it("drops Claude Code's own injected lines", () => {
+    const lines = chatLines([
+      msg({ sender: "user", content: [{ type: "text", text: "<command-name>/clear</command-name>" }] }),
+    ]);
+    expect(lines).toEqual([]);
+  });
+});