docs: improve CLAUDE.md structure and discoverability

- Move COM shorthand to prominent position after safety warning
- Add version sync note (must match package.json)
- Consolidate Key Files into 4 logical categories
- Clarify next available test port (3128)

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

src/web/public/index.html

@@ -536,6 +536,22 @@
               </label>
               <span class="form-hint">Show Monitor panel at bottom right</span>
             </div>
+            <div class="form-row form-row-switch">
+              <label>Enable Subagent Tracking</label>
+              <label class="switch">
+                <input type="checkbox" id="appSettingsSubagentTracking" checked>
+                <span class="slider"></span>
+              </label>
+              <span class="form-hint">Monitor Claude Code background agents in real-time</span>
+            </div>
+            <div class="form-row form-row-switch">
+              <label>Show Subagents Panel</label>
+              <label class="switch">
+                <input type="checkbox" id="appSettingsShowSubagents" checked>
+                <span class="slider"></span>
+              </label>
+              <span class="form-hint">Show the Subagents panel (independent from Monitor)</span>
+            </div>
           </div>
           <!-- Claude CLI Tab -->
           <div class="modal-tab-content hidden" id="settings-claude">