chore: import upstream snapshot with attribution

showcase/integrations/ag2/qa/shared-state-read-write.md

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+# QA: Shared State (Read + Write) — AG2
+
+## Prerequisites
+
+- Demo is deployed and accessible at `/demos/shared-state-read-write`
+- Agent backend is healthy (check `/api/copilotkit` GET → `agent_status: reachable`)
+- Backend has `OPENAI_API_KEY` set
+- The `shared-state-read-write` agent is mounted at `/shared-state-read-write` on
+  the FastAPI server (see `src/agent_server.py`)
+
+## Test Steps
+
+### 1. Page renders with the two cards and chat
+
+- [ ] Navigate to `/demos/shared-state-read-write`
+- [ ] Sidebar shows the **Preferences** card (`data-testid="preferences-card"`)
+- [ ] Sidebar shows the **Agent notes** card (`data-testid="notes-card"`) with the
+      empty state copy "No notes yet. Ask the agent to remember something."
+- [ ] Right-hand pane shows `<CopilotChat />` with the placeholder
+      "Chat with the agent..."
+- [ ] The "Shared state" panel inside the preferences card shows JSON with
+      `name: ""`, `tone: "casual"`, `language: "English"`, `interests: []`
+
+### 2. UI -> agent (write)
+
+- [ ] Type a name (e.g. `Atai`) into the **Name** input. The "Shared state"
+      JSON inside the card updates immediately to reflect the new name.
+- [ ] Change **Tone** to `playful`. JSON updates.
+- [ ] Change **Language** to `Spanish`. JSON updates.
+- [ ] Toggle 2-3 interests (e.g. `Cooking`, `Tech`). JSON updates and the
+      buttons show the selected style.
+- [ ] In the chat, send: **"Greet me in one sentence."**
+- [ ] The agent's reply addresses the user by name in a playful tone, in
+      Spanish (i.e. it actually used the preferences). It must NOT just
+      echo the JSON.
+
+### 3. agent -> UI (read)
+
+- [ ] In the chat, send: **"Remember that I prefer morning meetings and that
+      I don't eat dairy."**
+- [ ] The **Agent notes** card transitions from the empty state to a
+      bulleted list with at least 2 entries (`data-testid="note-item"`),
+      reflecting the two facts above. The list updates in real time
+      while/after the agent finishes its turn.
+- [ ] In the chat, send: **"Also remember I work in Pacific time."**
+- [ ] The notes list now has at least 3 entries (the agent passed the FULL
+      list to `set_notes`, not just the new one).
+
+### 4. Round-trip + Clear
+
+- [ ] Click the **Clear** button on the notes card.
+- [ ] The notes card returns to the empty state immediately.
+- [ ] In the chat, send: **"What do you remember about me?"**
+- [ ] The agent reports it has no remembered notes (because the UI cleared
+      them via `agent.setState`), confirming the UI's write-back was
+      visible to the agent on its next turn.
+
+### 5. Error handling
+
+- [ ] Send an empty message → handled gracefully (no crash, no broken UI).
+- [ ] No console errors during normal usage.
+
+## Expected Results
+
+- Page loads in < 3 seconds.
+- Preferences edits propagate to agent state instantly.
+- Agent replies adapt visibly to preferences (name, tone, language).
+- Notes card reflects every `set_notes` call from the agent.
+- Clearing notes from the UI is reflected on the agent's next turn.