feat: integrate template awareness into AI assistant

- Add template configurations with file structures and conventions
- Update AI route handler to include template context in system messages
- Pass template type through AIChat component
- Add template-specific run commands
- Enhance AI responses with project structure knowledge
- Move hardcoded run commands from navbar/run.tsx to templates/index.ts

This improves the AI's understanding of different project templates (React, Next.js, Streamlit, Vanilla JS) and enables more contextual assistance based on the project type.

frontend/components/editor/index.tsx

@@ -1233,6 +1233,7 @@ export default function CodeEditor({
                   editorRef={{ current: editorRef }}
                   lastCopiedRangeRef={lastCopiedRangeRef}
                   files={files}
+                  templateType={sandboxData.type}
                 />
               </ResizablePanel>
             </>