Add automatic template versioning system

- Add TEMPLATE_VERSION constant (1.3.0) to track UI changes
- Create check_template_version() to compare embedded vs current version
- Embed version marker as HTML comment in generated template
- Auto-regenerate template when version mismatch detected
- Show clear status messages: "Template up-to-date" or "regenerating"
- Document versioning system in CLAUDE.md with usage guidelines

Benefits:
- No manual template deletion required when code updates
- Users automatically get latest UI features on restart
- Clear version tracking for template changes
- Prevents stale template issues

To update template: increment TEMPLATE_VERSION when HTML/CSS/JS changes.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

CLAUDE.md

@@ -121,11 +121,28 @@ The entire Flask application lives in `rotary_phone_web.py` (~2000 lines). This
 - **Extra Button Sounds**: Separate PyAudio instance to prevent blocking main recording
 - **Hook Detection**: Direct GPIO reads during playback/recording loops for immediate response
 
-### HTML Template Generation
-The Flask app generates `templates/index.html` programmatically on first run. The template is defined as a string in the Python code and written to disk. To update the UI:
-1. Delete `templates/` directory
-2. Restart the application
-3. Updated template will be regenerated
+### HTML Template Generation and Versioning
+The Flask app generates `templates/index.html` programmatically with automatic version tracking:
+
+**Version System:**
+- `TEMPLATE_VERSION` constant (line ~84) tracks template changes
+- Version embedded as HTML comment: `<!-- TEMPLATE_VERSION: 1.3.0 -->`
+- `check_template_version()` compares embedded version with current code version
+- Template auto-regenerates on version mismatch
+
+**How It Works:**
+1. On startup, `check_template_version()` reads existing template
+2. If version matches `TEMPLATE_VERSION`, template is up-to-date
+3. If version mismatches or template missing, regeneration occurs automatically
+4. User sees: "Template up-to-date (v1.3.0)" or "Template version mismatch - regenerating"
+
+**When to Update:**
+- Increment `TEMPLATE_VERSION` whenever HTML/CSS/JS changes are made
+- Format: "X.Y.Z" (major.minor.patch)
+- Add comment describing the change
+
+**Manual Regeneration:**
+If needed, delete `templates/` directory and restart - not required with version system
 
 ## Configuration
 

rotary_phone_web.py

@@ -80,6 +80,9 @@ BACKUP_ON_WRITE = BACKUP_CONFIG.get('backup_on_write', True)
 # Web server settings
 WEB_PORT = SYS_CONFIG['web']['port']
 
+# Template version - increment this when HTML template changes
+TEMPLATE_VERSION = "1.3.0"  # Updated: Added download all recordings feature
+
 # Flask app
 app = Flask(__name__)
 app.config['MAX_CONTENT_LENGTH'] = SYS_CONFIG['web']['max_upload_size_mb'] * 1024 * 1024
@@ -924,6 +927,22 @@ def get_local_ip():
     except:
         return "127.0.0.1"
 
+def check_template_version(template_file):
+    """Check if template needs regeneration based on version"""
+    if not os.path.exists(template_file):
+        return False  # Template doesn't exist, needs creation
+
+    try:
+        with open(template_file, 'r') as f:
+            content = f.read()
+            # Look for version comment in template
+            if f'<!-- TEMPLATE_VERSION: {TEMPLATE_VERSION} -->' in content:
+                return True  # Version matches, no regeneration needed
+            else:
+                return False  # Version mismatch or missing, needs regeneration
+    except:
+        return False  # Error reading, regenerate to be safe
+
 def main():
     """Main entry point for the wedding phone application"""
     # Create templates directory and HTML template
@@ -931,14 +950,21 @@ def main():
     templates_dir = os.path.join(script_dir, 'templates')
     os.makedirs(templates_dir, exist_ok=True)
 
-    # Create the HTML template if it doesn't exist
+    # Check if template needs regeneration
     template_file = os.path.join(templates_dir, 'index.html')
-    if not os.path.exists(template_file):
-        print(f"Creating template at {template_file}")
+    template_up_to_date = check_template_version(template_file)
+
+    if not template_up_to_date:
+        if os.path.exists(template_file):
+            print(f"Template version mismatch - regenerating template at {template_file}")
+        else:
+            print(f"Creating new template at {template_file}")
+
         with open(template_file, 'w') as f:
-            f.write('''<!DOCTYPE html>
+            f.write(f'''<!DOCTYPE html>
 <html lang="en">
 <head>
+    <!-- TEMPLATE_VERSION: {TEMPLATE_VERSION} -->
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Rotary Phone Control Panel</title>
@@ -2030,8 +2056,8 @@ def main():
 </body>
 </html>''')
     else:
-        print(f"Template already exists at {template_file}")
-    
+        print(f"Template up-to-date (v{TEMPLATE_VERSION}) at {template_file}")
+
     # Start phone handling in separate thread
     phone_thread = threading.Thread(target=phone.phone_loop, daemon=True)
     phone_thread.start()