fix(ws): re-attach stateChange listeners when bot instance is replaced

startBot creates a fresh BotInstance but the WS layer keyed its listener
map by bot.id, so ensureAllBotsAttached skipped the new object and
stateChange events were never broadcast — the player bar only appeared
after a manual refresh. BotManager now extends EventEmitter and emits
"botInstance" whenever a new bot object is created; websocket.ts stores
the bot reference, detaches on replacement, and subscribes to the event
for immediate wiring.

Also enlarges the bot selector (padding 10×20, font 16, min-height 44,
bigger dot/chevron/state icons, wider name) and adds Playwright repro
scripts for the player bar bug and navbar sizing check.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/test_playbar.py

@@ -0,0 +1,105 @@
+"""Reproduce the player-bar-not-appearing bug."""
+import time
+import requests
+from playwright.sync_api import sync_playwright
+
+BASE = "http://localhost:3000"
+
+def get_bot_id():
+    r = requests.get(f"{BASE}/api/bot/")
+    return r.json()["bots"][0]["id"]
+
+def stop(bot_id):
+    requests.post(f"{BASE}/api/player/{bot_id}/stop")
+    requests.post(f"{BASE}/api/player/{bot_id}/clear")
+
+def play(bot_id, query="test"):
+    requests.post(f"{BASE}/api/player/{bot_id}/play", json={"query": query, "platform": "netease"})
+
+with sync_playwright() as p:
+    browser = p.chromium.launch(headless=True)
+    ctx = browser.new_context()
+    ctx.add_init_script("""
+      (() => {
+        const OrigWS = window.WebSocket;
+        window.__wsMessages = [];
+        window.WebSocket = function(...args) {
+          const ws = new OrigWS(...args);
+          ws.addEventListener('message', (ev) => {
+            try {
+              const d = JSON.parse(ev.data);
+              const summary = {type: d.type, botId: d.botId};
+              if (d.status) summary.playing = d.status.playing;
+              if (d.status?.currentSong) summary.song = d.status.currentSong.name;
+              window.__wsMessages.push(summary);
+              console.log('WS_MSG ' + JSON.stringify(summary));
+            } catch(e) {}
+          });
+          return ws;
+        };
+        Object.assign(window.WebSocket, OrigWS);
+      })();
+    """)
+    page = ctx.new_page()
+    logs = []
+    page.on("console", lambda msg: logs.append(f"[{msg.type}] {msg.text}"))
+
+    bot_id = get_bot_id()
+    stop(bot_id)
+    time.sleep(0.6)
+
+    page.goto(BASE)
+    page.wait_for_load_state("networkidle")
+    time.sleep(0.8)
+
+    # Hook into WebSocket messages from the page to confirm they arrive
+    page.evaluate("""
+      () => {
+        const origWS = window.WebSocket;
+        // Already connected via useWebSocket — tap Pinia store directly
+        // Expose store state via window
+        const store = window.__pinia?._s?.get('player');
+        window.__getStore = () => ({
+          bots: JSON.parse(JSON.stringify(store?.bots || [])),
+          activeBotId: store?.activeBotId,
+          currentSong: store?.currentSong ? JSON.parse(JSON.stringify(store.currentSong)) : null,
+          isPlaying: store?.isPlaying,
+        });
+      }
+    """)
+
+    snap_before = page.evaluate("() => window.__getStore?.()")
+    print("store before:", snap_before)
+
+    # Player bar should be absent right now (nothing playing)
+    initial = page.locator(".player-wrapper").count()
+    print(f"initial .player-wrapper count: {initial}")
+
+    # Trigger play via API (simulates any play trigger)
+    play(bot_id, "test")
+
+    # Poll for up to 6s to see if player bar appears automatically
+    appeared_at = None
+    for i in range(60):
+        if page.locator(".player-wrapper").count() > 0:
+            appeared_at = i * 0.1
+            break
+        page.wait_for_timeout(100)
+
+    print(f"player bar appeared after: {appeared_at}")
+    snap_after = page.evaluate("() => window.__getStore?.()")
+    print("store after:", snap_after)
+
+    # After force reload, does it appear?
+    if appeared_at is None:
+        page.reload()
+        page.wait_for_load_state("networkidle")
+        time.sleep(0.8)
+        after_reload = page.locator(".player-wrapper").count()
+        print(f"after reload .player-wrapper count: {after_reload}")
+
+    print("--- console logs ---")
+    for line in logs[-20:]:
+        print(line)
+
+    browser.close()