Fix code quality violations and exclude Manifest from checks

Document application modes (development/debug/production)
Add global file drop handler, order column normalization, SPA hash fix
Serve CDN assets via /_vendor/ URLs instead of merging into bundles
Add production minification with license preservation
Improve JSON formatting for debugging and production optimization
Add CDN asset caching with CSS URL inlining for production builds
Add three-mode system (development, debug, production)
Update Manifest CLAUDE.md to reflect helper class architecture
Refactor Manifest.php into helper classes for better organization
Pre-manifest-refactor checkpoint: Add app_mode documentation

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

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

node_modules/csso/lib/replace/Dimension.js

@@ -1,43 +1,44 @@
-var packNumber = require('./Number').pack;
-var MATH_FUNCTIONS = {
-    'calc': true,
-    'min': true,
-    'max': true,
-    'clamp': true
-};
-var LENGTH_UNIT = {
+import { packNumber } from './Number.js';
+
+const MATH_FUNCTIONS = new Set([
+    'calc',
+    'min',
+    'max',
+    'clamp'
+]);
+const LENGTH_UNIT = new Set([
     // absolute length units
-    'px': true,
-    'mm': true,
-    'cm': true,
-    'in': true,
-    'pt': true,
-    'pc': true,
+    'px',
+    'mm',
+    'cm',
+    'in',
+    'pt',
+    'pc',
 
     // relative length units
-    'em': true,
-    'ex': true,
-    'ch': true,
-    'rem': true,
+    'em',
+    'ex',
+    'ch',
+    'rem',
 
     // viewport-percentage lengths
-    'vh': true,
-    'vw': true,
-    'vmin': true,
-    'vmax': true,
-    'vm': true
-};
+    'vh',
+    'vw',
+    'vmin',
+    'vmax',
+    'vm'
+]);
 
-module.exports = function compressDimension(node, item) {
-    var value = packNumber(node.value, item);
+export default function compressDimension(node, item) {
+    const value = packNumber(node.value);
 
     node.value = value;
 
     if (value === '0' && this.declaration !== null && this.atrulePrelude === null) {
-        var unit = node.unit.toLowerCase();
+        const unit = node.unit.toLowerCase();
 
         // only length values can be compressed
-        if (!LENGTH_UNIT.hasOwnProperty(unit)) {
+        if (!LENGTH_UNIT.has(unit)) {
             return;
         }
 
@@ -49,14 +50,14 @@ module.exports = function compressDimension(node, item) {
         }
 
         // issue #222: don't remove units inside calc
-        if (this.function && MATH_FUNCTIONS.hasOwnProperty(this.function.name)) {
+        if (this.function && MATH_FUNCTIONS.has(this.function.name)) {
             return;
         }
 
         item.data = {
             type: 'Number',
             loc: node.loc,
-            value: value
+            value
         };
     }
 };