Move capture button left of search; always visible; disabled when server-disabled

- capture-btn moved to first child of trace-topbar (before search input)
- Button always visible: shows Start/Stop/Connect-to-server as before
- When server capture is disabled: grayed-out Start Capture with
  tooltip via existing i18n key 'Capture is disabled ...'
- No more hiding button when viewing saved session or when disabled
- Bump 1.22.4, SW cache v35->v36

frontend/index.html

@@ -114,6 +114,7 @@ body { font: 14px/1.5 system-ui, sans-serif; background: var(--bg); color: var(-
 .trace-topbar button.stop:hover { background: var(--danger-hover); }
 .trace-topbar button.connect { background: var(--warn); color: #0f172a; }
 .trace-topbar button.connect:hover { background: var(--warn-hover); }
+.trace-topbar button.disabled { background: var(--bg-input); color: var(--text-muted); cursor: not-allowed; opacity: 0.6; }
 .trace-main { display: flex; flex: 1; overflow: hidden; }
 .trace-left { flex: 1; display: flex; flex-direction: column; overflow: hidden; }
 
@@ -280,15 +281,15 @@ body { font: 14px/1.5 system-ui, sans-serif; background: var(--bg); color: var(-
     </div>
 </div><!-- Trace Panel -->
 <div class="panel active" id="panel-trace">
-    <div class="trace-topbar">
-        <input type="text" id="search-input" data-l10n="Search hex bytes..." placeholder="Search hex bytes..." autocomplete="off">
-        <label for="filter-select" class="filter-label" data-l10n="Filter">Filter</label>
-        <select id="filter-select">
-            <option value="" data-l10n="All commands">All commands</option>
-        </select>
-        <button id="capture-btn" data-l10n="Start Capture">Start Capture</button>
-        <span id="session-name-display" style="display:none; color:var(--text-muted); font-size:15px; font-weight:700;"></span>
-    </div>
+<div class="trace-topbar">
+    <button id="capture-btn" data-l10n="Start Capture">Start Capture</button>
+    <input type="text" id="search-input" data-l10n="Search hex bytes..." placeholder="Search hex bytes..." autocomplete="off">
+    <label for="filter-select" class="filter-label" data-l10n="Filter">Filter</label>
+    <select id="filter-select">
+        <option value="" data-l10n="All commands">All commands</option>
+    </select>
+    <span id="session-name-display" style="display:none; color:var(--text-muted); font-size:15px; font-weight:700;"></span>
+</div>
     <div class="trace-main">
         <div class="trace-left">
             <div class="apdu-list" id="apdu-list"></div>
@@ -2130,26 +2131,29 @@ async function stopCapture() {
 function updateCaptureButton() {
     const btn = el('capture-btn');
     const newCapture = el('new-capture-btn');
-    btn.classList.remove('stop', 'connect');
+    btn.classList.remove('stop', 'connect', 'disabled');
     const captureOff = STATE.captureMode === 'disabled' && STATE.serverAvailable;
     newCapture.style.display = captureOff ? 'none' : '';
-    if (captureOff) {
-        btn.style.display = 'none';
-        return;
-    }
-    if (STATE.sessionViewId && !STATE.captureActive) {
-        btn.style.display = 'none';
-        return;
-    }
     btn.style.display = '';
     if (!STATE.serverAvailable) {
         btn.textContent = t('Connect to server');
         btn.classList.add('connect');
+        btn.disabled = false;
+        btn.title = '';
+    } else if (captureOff) {
+        btn.textContent = t('Start Capture');
+        btn.classList.add('disabled');
+        btn.disabled = true;
+        btn.title = t('Capture is disabled — only pre-captured traces (saved sessions / PCAP import) are available.');
     } else if (STATE.captureActive) {
         btn.textContent = t('Stop Capture');
         btn.classList.add('stop');
+        btn.disabled = false;
+        btn.title = '';
     } else {
         btn.textContent = t('Start Capture');
+        btn.disabled = false;
+        btn.title = '';
     }
 }
 
@@ -2518,7 +2522,7 @@ function onFilterChange() {
 }
 
 // ──────────────────── Versioning ────────────────────
-const PWA_VERSION = '1.22.3';
+const PWA_VERSION = '1.22.4';
 const MIN_SERVER_VERSION = '1.0.0';
 
 function parseVersion(v) {

frontend/sw.js

@@ -1,4 +1,4 @@
-const CACHE = 'simtrace-analyser-v35';
+const CACHE = 'simtrace-analyser-v36';
 
 const PRECACHE = [
     'index.html',