feat: Object Editor Preview Mode & Mobile Optimizations

Major Enhancements:
- Added Preview/Edit mode toggle to StructuredEditor component
  * Preview mode: Read-only view with full text visibility
  * Edit mode: Full editing capabilities with all controls
  * Toggle positioned below title, responsive on mobile
  * Works in both main ObjectEditor view and nested modals

- Clickable nested data in Preview mode
  * JSON/serialized values are blue and clickable
  * Opens modal directly without switching to Edit mode
  * Hover effects and tooltips for better UX
  * No longer need edit mode just to explore structure

Mobile Responsiveness Improvements:
- Fixed all data load notices in ObjectEditor (URL, Paste, Open tabs)
- Fixed all data load notices in TableEditor (URL, Paste, Open tabs)
- Notices now stack vertically on mobile with proper spacing
- Added break-words for long text, whitespace-nowrap for buttons
- Dark mode colors added for better visibility

Table Editor Fixes:
- Fixed sticky header showing row underneath (top-[-1px])
- Made Export section header mobile responsive
- Updated object modal footer layout:
  * Format info and properties combined on single line
  * Buttons moved to separate row below
  * Changed 'Apply Changes' to 'Save Changes' for consistency

StructuredEditor Improvements:
- Moved overflow-x handling from ObjectEditor to StructuredEditor
- Now works consistently in main view and nested modals
- Long strings scroll horizontally everywhere
- 'Add Property' button hidden in Preview mode
- Improved chevron colors for dark mode visibility

Technical Changes:
- StructuredEditor now manages its own editMode state
- readOnly prop can still be passed from parent if needed
- Proper conditional rendering for all UI elements
- Consistent mobile-first responsive design patterns

package-lock.json

@@ -14,6 +14,7 @@
         "@codemirror/lang-html": "^6.4.9",
         "@codemirror/lang-javascript": "^6.2.4",
         "@codemirror/lang-json": "^6.0.2",
+        "@codemirror/lang-sql": "^6.10.0",
         "@codemirror/search": "^6.5.11",
         "@codemirror/state": "^6.5.2",
         "@codemirror/theme-one-dark": "^6.1.3",
@@ -2174,6 +2175,20 @@
         "@lezer/json": "^1.0.0"
       }
     },
+    "node_modules/@codemirror/lang-sql": {
+      "version": "6.10.0",
+      "resolved": "https://registry.npmjs.org/@codemirror/lang-sql/-/lang-sql-6.10.0.tgz",
+      "integrity": "sha512-6ayPkEd/yRw0XKBx5uAiToSgGECo/GY2NoJIHXIIQh1EVwLuKoU8BP/qK0qH5NLXAbtJRLuT73hx7P9X34iO4w==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/autocomplete": "^6.0.0",
+        "@codemirror/language": "^6.0.0",
+        "@codemirror/state": "^6.0.0",
+        "@lezer/common": "^1.2.0",
+        "@lezer/highlight": "^1.0.0",
+        "@lezer/lr": "^1.0.0"
+      }
+    },
     "node_modules/@codemirror/language": {
       "version": "6.11.3",
       "license": "MIT",