chore: update .gitignore and improve coding standards documentation

- Added .cursor/sessions/* to .gitignore to prevent session files from being tracked.
- Enhanced coding standards in SKILL.md by adding semicolons to TypeScript examples for consistency.
- Improved formatting in continuous learning, detail layout, and other SKILL.md files for better readability.

These changes aim to streamline development processes and maintain code quality across the project.

.agents/skills/security-review/SKILL.md

@@ -21,11 +21,11 @@ Client-side security for this React/Electron frontend. There is no NestJS API or
 
 ```typescript
 // NEVER
-const apiKey = "sk-proj-xxxxx"
+const apiKey = 'sk-proj-xxxxx';
 
 // ALWAYS
-import { ENV } from '../environment'
-if (!ENV.API_BASE_URL) throw new Error('VITE_API_BASE_URL is not configured')
+import { ENV } from '../environment';
+if (!ENV.API_BASE_URL) throw new Error('VITE_API_BASE_URL is not configured');
 ```
 
 - [ ] No hardcoded secrets