feat: implement zero-configuration auto-enhancement demo workflow

- Add intelligent auto-enhancement that detects viable content elements
- Replace manual enhancement with automated container-first detection
- Support inline formatting (strong, em, span, links) within editable content
- Streamline demo workflow: just demo shows options, auto-enhances on demand
- Clean up legacy commands and simplify directory structure
- Auto-enhancement goes directly from source to demo-ready (no intermediate dirs)
- Add Dan Eden portfolio and simple test sites for real-world validation
- Auto-enhanced 40 elements in Dan Eden portfolio, 5 in simple site
- Achieve true zero-configuration CMS experience

test-sites/simple/dan-eden-portfolio-demo/insertr-config.json

@@ -0,0 +1,22 @@
+{
+  "site_name": "Dan Eden Portfolio",
+  "description": "Personal portfolio site with clean design and minimal styling",
+  "base_url": "https://daneden.me",
+  "content_sections": [
+    {
+      "selector": ".home_xxl__iX0Z1",
+      "type": "markdown",
+      "editable": true,
+      "description": "Main bio paragraph - Product Designer intro"
+    },
+    {
+      "selector": "span.insertr",
+      "type": "text",
+      "editable": true,
+      "description": "Various text content elements (company, descriptions, titles)"
+    }
+  ],
+  "css_frameworks": ["Next.js CSS Modules"],
+  "complexity": "simple",
+  "testing_notes": "Clean Next.js site with CSS modules. Good test for CSS-in-JS compatibility and semantic HTML structure."
+}