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/cjs/restructure/2-initialMergeRuleset.cjs

@@ -0,0 +1,51 @@
+'use strict';
+
+const cssTree = require('css-tree');
+const utils = require('./utils.cjs');
+
+function processRule(node, item, list) {
+    const selectors = node.prelude.children;
+    const declarations = node.block.children;
+
+    list.prevUntil(item.prev, function(prev) {
+        // skip non-ruleset node if safe
+        if (prev.type !== 'Rule') {
+            return utils.unsafeToSkipNode.call(selectors, prev);
+        }
+
+        const prevSelectors = prev.prelude.children;
+        const prevDeclarations = prev.block.children;
+
+        // try to join rulesets with equal pseudo signature
+        if (node.pseudoSignature === prev.pseudoSignature) {
+            // try to join by selectors
+            if (utils.isEqualSelectors(prevSelectors, selectors)) {
+                prevDeclarations.appendList(declarations);
+                list.remove(item);
+                return true;
+            }
+
+            // try to join by declarations
+            if (utils.isEqualDeclarations(declarations, prevDeclarations)) {
+                utils.addSelectors(prevSelectors, selectors);
+                list.remove(item);
+                return true;
+            }
+        }
+
+        // go to prev ruleset if has no selector similarities
+        return utils.hasSimilarSelectors(selectors, prevSelectors);
+    });
+}
+
+// NOTE: direction should be left to right, since rulesets merge to left
+// ruleset. When direction right to left unmerged rulesets may prevent lookup
+// TODO: remove initial merge
+function initialMergeRule(ast) {
+    cssTree.walk(ast, {
+        visit: 'Rule',
+        enter: processRule
+    });
+}
+
+module.exports = initialMergeRule;