feat: add voice input mic button via Web Speech API

- index.html: add #btnMic (hidden by default, shown if browser supports
  SpeechRecognition) and #micStatus listening indicator inside .composer-box

- boot.js: IIFE-scoped mic handler wired to Web Speech API
  * recognition.continuous=false (auto-stops after ~2s silence)
  * recognition.interimResults=true (live transcript preview in textarea)
  * Toggles .recording class + shows #micStatus while active
  * Handles 'not-allowed', 'no-speech', 'network' errors via showToast()
  * btnSend.onclick stops active recognition before sending
  * Entire feature disabled/hidden gracefully when API unavailable

- style.css: .mic-btn, .mic-btn.recording (red pulse animation),
  .mic-status, .mic-dot, @keyframes mic-pulse

- tests/test_sprint20.py: 46 tests covering HTML structure, CSS rules,
  JS logic, error handling, and regression checks (376 total, all pass)

No API keys, no external libraries, no server changes. Browser-only.
Works in Chrome, Edge, Safari (partial). Firefox unsupported (hides button).

static/boot.js

@@ -8,8 +8,81 @@ async function cancelStream(){
   }catch(e){setStatus('Cancel failed: '+e.message);}
 }
 
-$('btnSend').onclick=send;
+$('btnSend').onclick=()=>{if(window._micActive)_stopMic();send();};
 $('btnAttach').onclick=()=>$('fileInput').click();
+
+// ── Voice input (Web Speech API) ─────────────────────────────────────────
+(function(){
+  const SpeechRecognition=window.SpeechRecognition||window.webkitSpeechRecognition;
+  if(!SpeechRecognition) return; // Browser unsupported — mic button stays hidden
+
+  const btn=$('btnMic');
+  const status=$('micStatus');
+  const ta=$('msg');
+  btn.style.display=''; // Show button — browser supports speech
+
+  const recognition=new SpeechRecognition();
+  recognition.continuous=false;
+  recognition.interimResults=true;
+  recognition.lang='en-US';
+
+  let _finalText='';
+
+  function _setRecording(on){
+    window._micActive=on;
+    btn.classList.toggle('recording',on);
+    status.style.display=on?'':'none';
+    if(!on) _finalText='';
+  }
+
+  recognition.onstart=()=>{ _finalText=''; };
+
+  recognition.onresult=(event)=>{
+    let interim='';
+    let final=_finalText;
+    for(let i=event.resultIndex;i<event.results.length;i++){
+      const t=event.results[i][0].transcript;
+      if(event.results[i].isFinal){ final+=t; _finalText=final; }
+      else{ interim+=t; }
+    }
+    ta.value=final||interim;
+    autoResize();
+  };
+
+  recognition.onend=()=>{
+    _setRecording(false);
+    // Ensure textarea has the committed final text (handles auto-stop on silence)
+    if(_finalText) ta.value=_finalText;
+    autoResize();
+  };
+
+  recognition.onerror=(event)=>{
+    _setRecording(false);
+    const msgs={
+      'not-allowed':'Microphone access denied. Check browser permissions.',
+      'no-speech':'No speech detected. Try again.',
+      'network':'Speech recognition unavailable.',
+    };
+    showToast(msgs[event.error]||'Voice input error: '+event.error);
+  };
+
+  function _stopMic(){
+    if(window._micActive){ recognition.stop(); }
+  }
+  window._stopMic=_stopMic; // expose for send-guard above
+
+  btn.onclick=()=>{
+    if(window._micActive){
+      recognition.stop();
+      // _setRecording(false) will be called by onend
+    } else {
+      _finalText='';
+      recognition.start();
+      _setRecording(true);
+    }
+  };
+})();
+window._micActive=window._micActive||false;
 $('fileInput').onchange=e=>{addFiles(Array.from(e.target.files));e.target.value='';};
 $('btnNewChat').onclick=async()=>{await newSession();await renderSessionList();$('msg').focus();};
 $('btnDownload').onclick=()=>{

static/index.html

@@ -213,6 +213,7 @@
           Drop files to upload to workspace
         </div>
         <div class="attach-tray" id="attachTray"></div>
+        <div class="mic-status" id="micStatus" style="display:none"><span class="mic-dot"></span> Listening…</div>
         <textarea id="msg" rows="1" placeholder="Message Hermes…"></textarea>
         <div class="composer-footer">
           <div class="composer-left">
@@ -220,6 +221,14 @@
             <button class="icon-btn" id="btnAttach" title="Attach files">
               <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21.44 11.05l-9.19 9.19a6 6 0 0 1-8.49-8.49l9.19-9.19a4 4 0 0 1 5.66 5.66l-9.2 9.19a2 2 0 0 1-2.83-2.83l8.49-8.48"/></svg>
             </button>
+            <button class="icon-btn mic-btn" id="btnMic" title="Voice input" style="display:none">
+              <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+                <rect x="9" y="1" width="6" height="12" rx="3"/>
+                <path d="M5 10a7 7 0 0 0 14 0"/>
+                <line x1="12" y1="19" x2="12" y2="23"/>
+                <line x1="8" y1="23" x2="16" y2="23"/>
+              </svg>
+            </button>
           </div>
           <div class="composer-right">
             <button class="send-btn" id="btnSend">

static/style.css

@@ -187,6 +187,11 @@
   .icon-btn{width:34px;height:34px;border-radius:8px;background:none;border:none;color:var(--muted);cursor:pointer;display:flex;align-items:center;justify-content:center;font-size:16px;transition:all .15s;}
   .icon-btn{opacity:.75;}
   .icon-btn:hover{background:rgba(255,255,255,.08);color:var(--text);opacity:1;}
+  .mic-btn{transition:color .15s,background .15s;}
+  .mic-btn.recording{color:#e94560;background:rgba(233,69,96,.12);animation:mic-pulse 1.2s ease-in-out infinite;}
+  @keyframes mic-pulse{0%,100%{box-shadow:0 0 0 0 rgba(233,69,96,.3);}50%{box-shadow:0 0 0 6px rgba(233,69,96,0);}}
+  .mic-status{font-size:11px;color:#e94560;padding:4px 12px;display:flex;align-items:center;gap:6px;}
+  .mic-dot{width:6px;height:6px;border-radius:50%;background:#e94560;animation:mic-pulse 1.2s ease-in-out infinite;flex-shrink:0;}
   .status-text{font-size:11px;color:var(--muted);padding-left:4px;}
   .send-btn{padding:7px 18px;border-radius:10px;font-size:13px;font-weight:600;background:linear-gradient(135deg,#5ba8f5,#7cb9ff);border:none;color:#0a1628;cursor:pointer;display:flex;align-items:center;gap:6px;transition:all .15s;flex-shrink:0;letter-spacing:.01em;}
   .send-btn:hover{background:linear-gradient(135deg,#7cb9ff,#a0d0ff);transform:translateY(-1px);}