feat: implement auto-injection of insertr.js with site-specific configuration

• Add /insertr.js endpoint to serve JavaScript library from API server
• Implement demo gate auto-injection for sites without existing gates
• Add dynamic site ID injection using per-demo configuration files
• Fix CORS middleware to support localhost origins on any port
• Update demo commands to use individual insertr.yaml configs
• Resolve content persistence issues by matching site IDs between injection and enhancement
• Enable complete edit/save workflow for demo sites with proper namespace isolation

test-sites/simple/test-simple/insertr.yaml

@@ -0,0 +1,27 @@
+# Insertr Configuration for Simple Demo Site
+# Specific configuration for the simple test site demo
+
+# Global settings
+dev_mode: true           # Development mode for demos
+
+# Database configuration  
+database:
+  path: "./insertr.db"   # Shared database with main config
+
+# Demo-specific configuration
+demo:
+  site_id: "simple"      # Unique site ID for simple demo
+  inject_demo_gate: true # Auto-inject demo gate if no gates exist
+  mock_auth: true        # Use mock authentication for demos
+  api_endpoint: "http://localhost:8080/api/content"
+  demo_port: 3000        # Port for live-server
+
+# CLI enhancement configuration
+cli:
+  site_id: "simple"      # Site ID for this demo
+  output: "./simple-demo" # Output directory for enhanced files
+  inject_demo_gate: true # Inject demo gate in development mode
+
+# Authentication configuration (for demo)
+auth:
+  provider: "mock"       # Mock auth for demos