Fix code quality violations for publish

Remove unused blade settings pages not linked from UI
Convert remaining frontend pages to SPA actions
Convert settings user_settings and general to SPA actions
Convert settings profile pages to SPA actions
Convert contacts and projects add/edit pages to SPA actions
Convert clients add/edit page to SPA action with loading pattern
Refactor component scoped IDs from $id to $sid
Fix jqhtml comment syntax and implement universal error component system
Update all application code to use new unified error system
Remove all backwards compatibility - unified error system complete
Phase 5: Remove old response classes
Phase 3-4: Ajax response handler sends new format, old helpers deprecated
Phase 2: Add client-side unified error foundation
Phase 1: Add server-side unified error foundation
Add unified Ajax error response system with constants

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

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

node_modules/@jqhtml/webpack-loader/README.md

@@ -139,10 +139,10 @@ Use `@event` syntax for event handling:
 
 ### Scoped IDs
 
-Use `$id` for component-scoped element IDs:
+Use `$sid` for component-scoped element IDs:
 
 ```jqhtml
-<div $id="content">
+<div $sid="content">
   <!-- Becomes id="content:abc123" where abc123 is the component's _cid -->
 </div>
 ```
@@ -150,7 +150,7 @@ Use `$id` for component-scoped element IDs:
 Access in component:
 
 ```javascript
-this.$id('content') // Returns jQuery element
+this.$sid('content') // Returns jQuery element
 ```
 
 ## Advanced Configuration