feat(ui): improve respawn duration with preset buttons

Replace the simple number input for respawn duration with a preset
button group (30m, 1h, 2h, 4h, 8h, ∞, Custom). Move duration to be
the first option in the Respawn Controller settings.

- Add duration preset buttons with visual highlighting for selection
- ∞ (unlimited) is selected by default
- Custom option reveals a number input for arbitrary values
- Reset to default when modal opens

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/web/public/app.js

@@ -1302,20 +1302,60 @@ class ClaudemanApp {
       respawnSection.style.display = 'none';
     }
 
+    // Reset duration presets to default (unlimited)
+    this.selectDurationPreset('');
+
     document.getElementById('sessionOptionsModal').classList.add('active');
 
     // Focus the name input
     setTimeout(() => document.getElementById('sessionNameInput').focus(), 100);
   }
 
+  // Handle duration preset selection
+  selectDurationPreset(value) {
+    // Remove active from all buttons
+    document.querySelectorAll('.duration-preset-btn').forEach(btn => btn.classList.remove('active'));
+
+    // Find and activate the clicked button
+    const btn = document.querySelector(`.duration-preset-btn[data-minutes="${value}"]`);
+    if (btn) btn.classList.add('active');
+
+    // Show/hide custom input
+    const customInput = document.querySelector('.duration-custom-input');
+    const durationInput = document.getElementById('modalRespawnDuration');
+
+    if (value === 'custom') {
+      customInput.classList.add('visible');
+      durationInput.focus();
+    } else {
+      customInput.classList.remove('visible');
+      durationInput.value = ''; // Clear custom value when using preset
+    }
+  }
+
+  // Get selected duration from preset buttons or custom input
+  getSelectedDuration() {
+    const customInput = document.querySelector('.duration-custom-input');
+    const durationInput = document.getElementById('modalRespawnDuration');
+
+    if (customInput.classList.contains('visible')) {
+      // Custom mode - use input value
+      return durationInput.value ? parseInt(durationInput.value) : null;
+    } else {
+      // Preset mode - get from active button
+      const activeBtn = document.querySelector('.duration-preset-btn.active');
+      const minutes = activeBtn?.dataset.minutes;
+      return minutes ? parseInt(minutes) : null;
+    }
+  }
+
   // Get respawn config from modal inputs
   getModalRespawnConfig() {
     const updatePrompt = document.getElementById('modalRespawnPrompt').value;
     const sendClear = document.getElementById('modalRespawnSendClear').checked;
     const sendInit = document.getElementById('modalRespawnSendInit').checked;
     const kickstartPrompt = document.getElementById('modalRespawnKickstart').value.trim() || undefined;
-    const durationStr = document.getElementById('modalRespawnDuration').value;
-    const durationMinutes = durationStr ? parseInt(durationStr) : null;
+    const durationMinutes = this.getSelectedDuration();
 
     // Auto-compact settings
     const autoCompactEnabled = document.getElementById('modalAutoCompactEnabled').checked;

src/web/public/index.html

@@ -209,17 +209,28 @@
             </div>
 
             <div class="form-row">
-              <label>Update Prompt</label>
-              <input type="text" id="modalRespawnPrompt" value="update all the docs and CLAUDE.md" placeholder="Prompt to send when idle">
+              <label>Run Duration</label>
+              <div class="duration-presets">
+                <button type="button" class="duration-preset-btn" data-minutes="30" onclick="app.selectDurationPreset('30')">30m</button>
+                <button type="button" class="duration-preset-btn" data-minutes="60" onclick="app.selectDurationPreset('60')">1h</button>
+                <button type="button" class="duration-preset-btn" data-minutes="120" onclick="app.selectDurationPreset('120')">2h</button>
+                <button type="button" class="duration-preset-btn" data-minutes="240" onclick="app.selectDurationPreset('240')">4h</button>
+                <button type="button" class="duration-preset-btn" data-minutes="480" onclick="app.selectDurationPreset('480')">8h</button>
+                <button type="button" class="duration-preset-btn active" data-minutes="" onclick="app.selectDurationPreset('')">∞</button>
+                <div class="duration-custom">
+                  <button type="button" class="duration-preset-btn" data-minutes="custom" onclick="app.selectDurationPreset('custom')">Custom</button>
+                  <div class="input-suffix input-suffix-sm duration-custom-input">
+                    <input type="number" id="modalRespawnDuration" value="" min="1" placeholder="min">
+                    <span>min</span>
+                  </div>
+                </div>
+              </div>
+              <span class="form-hint">How long to run the respawn loop</span>
             </div>
 
             <div class="form-row">
-              <label>Run Duration</label>
-              <div class="input-suffix">
-                <input type="number" id="modalRespawnDuration" value="" min="1" placeholder="No limit">
-                <span>min</span>
-              </div>
-              <span class="form-hint">Leave empty for unlimited. Respawn stops after duration.</span>
+              <label>Update Prompt</label>
+              <input type="text" id="modalRespawnPrompt" value="update all the docs and CLAUDE.md" placeholder="Prompt to send when idle">
             </div>
 
             <div class="form-row">

src/web/public/styles.css

@@ -1351,6 +1351,54 @@ body {
   font-size: 0.7rem;
 }
 
+/* Duration preset buttons */
+.duration-presets {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.35rem;
+  align-items: center;
+}
+
+.duration-preset-btn {
+  padding: 0.4rem 0.7rem;
+  font-size: 0.75rem;
+  background: var(--bg-input);
+  border: 1px solid var(--border);
+  border-radius: 4px;
+  color: var(--text-dim);
+  cursor: pointer;
+  transition: all 0.15s;
+}
+
+.duration-preset-btn:hover {
+  border-color: var(--border-light);
+  color: var(--text);
+}
+
+.duration-preset-btn.active {
+  background: var(--accent);
+  border-color: var(--accent);
+  color: #fff;
+}
+
+.duration-custom {
+  display: flex;
+  align-items: center;
+  gap: 0.35rem;
+}
+
+.duration-custom-input {
+  display: none;
+}
+
+.duration-custom-input.visible {
+  display: flex;
+}
+
+.duration-custom-input input {
+  width: 60px;
+}
+
 /* Respawn actions in modal */
 .respawn-actions {
   display: flex;