Render single-select clarify prompts as interactive pickers

Clarify questions with a finite option set now render as the same
tappable picker card used by /reasoning and /fast, instead of a numbered
text list. The change is gateway-only: it reuses the existing
picker.choice frame and the app's PickerCard UI, so no app change or
reinstall is needed.

- send_clarify: single-select + live device emits a picker.choice frame
  (one button per option + an "Other (type your answer)" button) and
  registers a pending picker; the selection resolves via
  resolve_gateway_clarify (the agent then continues and replies).
- "Other" flips the entry to text-capture (mark_awaiting_text) and
  prompts the user to type; an unmappable value also flips to text so a
  clarify never dead-ends.
- Multi-select, open-ended, and no-live-device clarifies keep the
  numbered-text fallback (unchanged behavior).
- New helpers _clarify_is_multi / _clarify_picker_callback; positional
  option values (c0..cN, other) mirror the relay adapter.

Tests: updated test_clarify_emits_banner_and_message to multi-select
(text fallback) + 3 new tests (single-select emits picker & resolves,
Other flips to text, no-device falls back to text). Full suite 90/90.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

gateway-plugin/tests/test_android.py

@@ -1945,7 +1945,9 @@ async def test_clarify_emits_banner_and_message(adapter, ws_client):
     ws, _ = ws_client
     from tools import clarify_gateway as cg
 
-    cg.register("cl_1", "sk", "Which one?", ["A", "B"])
+    # Multi-select forces the numbered-text fallback (single-select with a live
+    # device now renders a picker -- see test_clarify_single_select_emits_picker).
+    cg.register("cl_1", "sk", "Which one?", ["A", "B"], multi_select=True)
     try:
         res = await adapter.send_clarify(
             "default", "Which one?", ["A", "B"], "cl_1", "sk"
@@ -1965,6 +1967,98 @@ async def test_clarify_emits_banner_and_message(adapter, ws_client):
         cg._session_index.pop("sk", None)
 
 
+@pytest.mark.asyncio
+async def test_clarify_single_select_emits_picker(plugin, adapter, ws_client):
+    """Single-select clarify with a live device renders as a picker.choice
+    card (options + Other). Tapping an option resolves the clarify with the
+    choice text; the picker is consumed."""
+    ws, _ = ws_client
+    from tools import clarify_gateway as cg
+
+    cg.register("cl_pk1", "sk", "Which one?", ["A", "B"])
+    try:
+        res = await adapter.send_clarify("default", "Which one?", ["A", "B"], "cl_pk1", "sk")
+        assert res.success
+        frames = await recv_until(ws, lambda f: f.get("type") == "picker.choice")
+        pc = frames[-1]
+        pid = pc["payload"]["picker_id"]
+        assert pid == res.message_id
+        assert pc["payload"]["title"] == "❓ Which one?"
+        assert [c["value"] for c in pc["payload"]["choices"]] == ["c0", "c1", "other"]
+        assert [c["label"] for c in pc["payload"]["choices"]] == [
+            "A",
+            "B",
+            "✏️ Other (type your answer)",
+        ]
+        # Tap "A" (c0) -> resolves the clarify with the choice text.
+        await ws.send(
+            json.dumps(
+                {"type": "picker.select", "id": 1, "payload": {"picker_id": pid, "value": "c0"}}
+            )
+        )
+        entry = cg._entries.get("cl_pk1")
+        for _ in range(50):
+            if entry.event.is_set():
+                break
+            await asyncio.sleep(0.05)
+        assert entry.event.is_set()
+        assert entry.response == "A"
+        assert pid not in adapter._pending_pickers
+    finally:
+        cg._entries.pop("cl_pk1", None)
+        cg._session_index.pop("sk", None)
+
+
+@pytest.mark.asyncio
+async def test_clarify_picker_other_flips_to_text(plugin, adapter, ws_client):
+    """Tapping 'Other' on a clarify picker flips the entry to text-capture
+    (awaiting_text) and prompts the user to type; the clarify is NOT resolved."""
+    ws, _ = ws_client
+    from tools import clarify_gateway as cg
+
+    cg.register("cl_pk2", "sk", "Which one?", ["A", "B"])
+    try:
+        res = await adapter.send_clarify("default", "Which one?", ["A", "B"], "cl_pk2", "sk")
+        assert res.success
+        frames = await recv_until(ws, lambda f: f.get("type") == "picker.choice")
+        pid = frames[-1]["payload"]["picker_id"]
+        await ws.send(
+            json.dumps(
+                {"type": "picker.select", "id": 1, "payload": {"picker_id": pid, "value": "other"}}
+            )
+        )
+        frames2 = await recv_until(
+            ws,
+            lambda f: f.get("type") == "message"
+            and "Type your answer" in f["payload"].get("text", ""),
+        )
+        assert frames2[-1]["payload"]["role"] == "assistant"
+        entry = cg._entries.get("cl_pk2")
+        assert entry.awaiting_text is True
+        assert not entry.event.is_set()
+    finally:
+        cg._entries.pop("cl_pk2", None)
+        cg._session_index.pop("sk", None)
+
+
+@pytest.mark.asyncio
+async def test_clarify_single_select_no_device_falls_back_to_text(adapter):
+    """Single-select clarify with NO live device falls back to the numbered
+    text list (no picker) and enables text-capture."""
+    from tools import clarify_gateway as cg
+
+    cg.register("cl_pk3", "sk", "Which one?", ["A", "B"])
+    try:
+        res = await adapter.send_clarify("default", "Which one?", ["A", "B"], "cl_pk3", "sk")
+        assert res.success
+        assert not adapter._pending_pickers
+        entry = cg._entries.get("cl_pk3")
+        assert entry.awaiting_text is True
+    finally:
+        cg._entries.pop("cl_pk3", None)
+        cg._session_index.pop("sk", None)
+
+
 # ── M5: sync catch-up + outbox row cap ─────────────────────────────────────