refactor: replace QueryEditor with SqlEditor component

- Create focused SqlEditor component for SQL editing with intellisense
- Remove unused QueryEditor component and its styles
- Integrate SqlEditor into QueryWorkspace to eliminate code duplication
- Fix TypeScript errors in intellisense implementation
- Add required range property to Monaco completion items
- Update documentation to reflect new architecture

Author: sahithvibudhi

CLAUDE.md

@@ -32,7 +32,7 @@ src/
     │   ├── DatabaseConnection/      # Connection dialog/form
     │   ├── DatabaseExplorer/        # Database tree view
     │   ├── Layout/                  # Layout components
-    │   ├── QueryEditor/             # SQL editor component
+    │   ├── QueryWorkspace/          # Query workspace with SQL editor
     │   ├── QueryResults/            # Results grid
     │   └── ThemeSwitcher/           # Theme selection dropdown
     └── lib/
@@ -57,7 +57,7 @@ Currently supports:
 1. **No Connection**: Shows MainPanel with connection options and saved connections
 2. **Active Connection**: Shows ActiveConnectionLayout with:
    - DatabaseExplorer (left panel, resizable)
-   - QueryWorkspace (right panel) containing QueryEditor and QueryResults
+   - QueryWorkspace (right panel) containing SqlEditor and QueryResults
 
 ## Development Guidelines
 
@@ -114,7 +114,7 @@ npm run typecheck  # if available
 - Implement actual database connection logic
 - Add database-specific drivers (pg, mysql2, etc.)
 - Implement tree view in DatabaseExplorer
-- Add query execution in QueryEditor
+- Query execution is implemented in QueryWorkspace with SQL intellisense
 - Implement results display in QueryResults
 
 ## Important Notes

README.md

@@ -86,7 +86,6 @@ data-pup/
 │       │   ├── ActiveConnectionLayout/ # Main connected view
 │       │   ├── ConnectionCard/     # Connection display cards
 │       │   ├── DatabaseExplorer/   # Database tree view
-│       │   ├── QueryEditor/        # SQL editor component
 │       │   ├── QueryHistory/       # Query history panel
 │       │   ├── QueryTabs/          # Tab management
 │       │   ├── QueryWorkspace/     # Query workspace container

src/renderer/components/Layout/MainPanel.tsx

@@ -1,7 +1,6 @@
-import { Box, Flex, Text, Button, ScrollArea, Heading } from '@radix-ui/themes'
-import { Card, Logo } from '../ui'
+import { Box, Flex, Text, Button, Heading } from '@radix-ui/themes'
+import { Logo } from '../ui'
 import { DatabaseConnection } from '../DatabaseConnection/DatabaseConnection'
-import { QueryEditor } from '../QueryEditor/QueryEditor'
 import { ThemeSwitcher } from '../ThemeSwitcher'
 import { ActiveConnectionLayout } from '../ActiveConnectionLayout'
 import { ConnectionCard, ConnectionCardSkeleton } from '../ConnectionCard'