feat: play the Nth YouTube result in browseAndPlay via an index arg

agents/llm.md promises "play the Nth video from the top", but browseAndPlay
only ever clicked the first result. Add an optional 1-based index argument
(default 1, backward-compatible) threaded to the Node helper, which now clicks
the Nth a#video-title and clamps to the number of results returned so asking
beyond the list plays the last available video instead of failing.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/jarvis/tools/builtin/browse_and_play.py

@@ -30,8 +30,10 @@ class BrowseAndPlayTool(Tool):
     def description(self) -> str:
         return (
             "Play a song / music video / clip on the shared screen by searching YouTube "
-            "and playing the first result. Use when the user asks you to play or watch "
-            "something. Only available in screen-share mode."
+            "and playing a result. Use when the user asks you to play or watch "
+            "something. Plays the first result by default; pass 'index' to play the "
+            "Nth result from the top of the search list (e.g. 'play the 3rd video' -> "
+            "index=3). Only available in screen-share mode."
         )
 
     @property
@@ -42,7 +44,16 @@ class BrowseAndPlayTool(Tool):
                 "query": {
                     "type": "string",
                     "description": "What to play, e.g. 'IU Good Day' or 'lofi hip hop'.",
-                }
+                },
+                "index": {
+                    "type": "integer",
+                    "description": (
+                        "1-based position of the video to play in the search results, "
+                        "counted from the top of the list. Defaults to 1 (first result). "
+                        "Use for 'play the Nth video' / 'play the second one'."
+                    ),
+                    "minimum": 1,
+                },
             },
             "required": ["query"],
         }
@@ -55,18 +66,25 @@ class BrowseAndPlayTool(Tool):
                 reply_text="화면 공유 모드(STREAM_BROWSER=true)에서만 영상을 재생할 수 있습니다.",
             )
         query = ""
+        index = 1
         if args and isinstance(args, dict):
             query = str(args.get("query", "")).strip()
+            try:
+                index = int(args.get("index", 1) or 1)
+            except (TypeError, ValueError):
+                index = 1
+            if index < 1:
+                index = 1
         if not query:
             return ToolExecutionResult(success=False, reply_text="재생할 내용을 알려주세요.")
         if not _NODE_SCRIPT.exists():
             return ToolExecutionResult(success=False, reply_text="브라우저 재생 도구를 찾을 수 없습니다.")
 
-        context.user_print(f"▶️ 화면에서 '{query}' 재생 중…")
-        debug_log(f"    ▶️ browseAndPlay '{query}'", "tools")
+        context.user_print(f"▶️ 화면에서 '{query}' 재생 중… (#{index})")
+        debug_log(f"    ▶️ browseAndPlay '{query}' index={index}", "tools")
         try:
             proc = subprocess.run(
-                ["node", str(_NODE_SCRIPT), query, "youtube"],
+                ["node", str(_NODE_SCRIPT), query, "youtube", str(index)],
                 capture_output=True,
                 text=True,
                 timeout=40,

src/jarvis/tools/builtin/browse_and_play.spec.md

@@ -6,16 +6,24 @@ video, or clip.
 
 ### Behaviour
 
-- Public schema is a single required `query` string (what to play).
+- Public schema is a required `query` string (what to play) plus an optional
+  `index` integer (1-based position in the search results, counted from the top
+  of the list). `index` defaults to `1` (first result), so existing callers and
+  "play X" requests are unchanged; "play the 3rd video" / "play the second one"
+  map to `index=3` / `index=2`.
 - **Mode-gated**: only acts when `STREAM_BROWSER` is true (`cfg.stream_browser`).
   In voice-only mode (false) there is no screen to show, so it returns a short
   message and does nothing.
 - Drives the on-screen Chrome by subprocessing the Node CDP helper
-  `bot/scripts/stream-test/browse-search.mjs <query> youtube`, which searches
-  YouTube and plays the first result on display `:1`. The broadcast captures
-  that display, so the playback is what viewers see.
-- Returns `success` with the played video's title, or a failure message if the
-  helper/Chrome is unavailable. It does NOT make an LLM call.
+  `bot/scripts/stream-test/browse-search.mjs <query> youtube <index>`, which
+  searches YouTube and plays the chosen result on display `:1`. The broadcast
+  captures that display, so the playback is what viewers see.
+  - The helper clicks the `index`-th `a#video-title` in the results list. The
+    index is clamped to the number of results actually returned, so asking for a
+    position beyond the list plays the last available result rather than failing.
+- Returns `success` with the played video's title (and the resolved `index`), or
+  a failure message if the helper/Chrome is unavailable. It does NOT make an LLM
+  call.
 
 ### Principles