feat: add manual file enhancement with development mode support

- Add manual enhance API endpoint (POST /api/enhance?site_id={site}) for triggering file enhancement
- Implement enhance button in JavaScript library status indicator (🔄 Enhance)
- Disable auto-enhancement in development mode to prevent live-reload conflicts
- Add dev mode parameter to SiteManager to control enhancement behavior
- Update API routing structure to support /api/enhance endpoint
- Include enhance button styling and user feedback (loading, success, error states)
- Button triggers file enhancement and page reload to show updated static files

Development workflow improvements:
- Content edits → Immediate editor preview (no unwanted page reloads)
- Manual enhance button → Intentional file updates + reload for testing
- Production mode maintains automatic enhancement on content changes

This resolves the live-reload conflict where automatic file enhancement
was causing unwanted page reloads during content editing in development.

lib/src/core/auth.js

@@ -330,11 +330,15 @@ export class InsertrAuth {
                     <span class="insertr-status-text">Visitor Mode</span>
                     <span class="insertr-status-dot"></span>
                 </div>
+                <button id="insertr-enhance-btn" class="insertr-enhance-btn" style="display: none;" title="Enhance files with latest content">
+                    🔄 Enhance
+                </button>
             </div>
         `;
 
         document.body.insertAdjacentHTML('beforeend', statusHtml);
         this.statusIndicator = document.getElementById('insertr-status');
+        this.setupEnhanceButton();
         this.updateStatusIndicator();
     }
 
@@ -357,6 +361,9 @@ export class InsertrAuth {
             statusText.textContent = 'Authenticated';
             statusDot.className = 'insertr-status-dot insertr-status-authenticated';
         }
+
+        // Update enhance button visibility
+        this.updateEnhanceButtonVisibility();
     }
 
     /**
@@ -398,6 +405,28 @@ export class InsertrAuth {
             body.insertr-hide-gates .insertr-gate {
                 display: none !important;
             }
+
+            /* Enhance button styles */
+            .insertr-enhance-btn {
+                background: #2563eb;
+                color: white;
+                border: none;
+                padding: 4px 8px;
+                border-radius: 4px;
+                font-size: 11px;
+                margin-left: 8px;
+                cursor: pointer;
+                transition: background 0.2s ease;
+            }
+
+            .insertr-enhance-btn:hover {
+                background: #1d4ed8;
+            }
+
+            .insertr-enhance-btn:disabled {
+                background: #9ca3af;
+                cursor: not-allowed;
+            }
         `;
 
         const styleSheet = document.createElement('style');
@@ -556,4 +585,85 @@ export class InsertrAuth {
             console.log('✅ OAuth authentication successful');
         }, 1000);
     }
+
+    /**
+     * Setup enhance button functionality
+     */
+    setupEnhanceButton() {
+        const enhanceBtn = document.getElementById('insertr-enhance-btn');
+        if (!enhanceBtn) return;
+
+        enhanceBtn.addEventListener('click', async () => {
+            await this.enhanceFiles();
+        });
+
+        // Show enhance button only in development/authenticated mode
+        this.updateEnhanceButtonVisibility();
+    }
+
+    /**
+     * Update enhance button visibility based on authentication state
+     */
+    updateEnhanceButtonVisibility() {
+        const enhanceBtn = document.getElementById('insertr-enhance-btn');
+        if (!enhanceBtn) return;
+
+        // Show enhance button when authenticated (indicates dev mode)
+        if (this.state.isAuthenticated) {
+            enhanceBtn.style.display = 'inline-block';
+        } else {
+            enhanceBtn.style.display = 'none';
+        }
+    }
+
+    /**
+     * Trigger manual file enhancement
+     */
+    async enhanceFiles() {
+        const enhanceBtn = document.getElementById('insertr-enhance-btn');
+        if (!enhanceBtn) return;
+
+        // Get site ID from window context or configuration
+        const siteId = window.insertrConfig?.siteId || this.options.siteId || 'demo';
+
+        try {
+            // Show loading state
+            enhanceBtn.textContent = '⏳ Enhancing...';
+            enhanceBtn.disabled = true;
+
+            // Call enhance API
+            const response = await fetch(`/api/enhance?site_id=${siteId}`, {
+                method: 'POST',
+                headers: {
+                    'Content-Type': 'application/json',
+                    'Authorization': `Bearer ${this.state.currentUser?.token || 'mock-token'}`
+                }
+            });
+
+            if (!response.ok) {
+                throw new Error(`Enhancement failed: ${response.status} ${response.statusText}`);
+            }
+
+            const result = await response.json();
+            console.log('✅ Files enhanced successfully:', result);
+
+            // Show success state briefly
+            enhanceBtn.textContent = '✅ Enhanced!';
+            
+            // Optional: Trigger page reload to show enhanced files
+            setTimeout(() => {
+                window.location.reload();
+            }, 1000);
+
+        } catch (error) {
+            console.error('❌ Enhancement failed:', error);
+            enhanceBtn.textContent = '❌ Failed';
+            
+            // Reset button after error
+            setTimeout(() => {
+                enhanceBtn.textContent = '🔄 Enhance';
+                enhanceBtn.disabled = false;
+            }, 2000);
+        }
+    }
 }