Add new skills for backend patterns, coding standards, continuous learning, and NestJS best practices

- Introduced backend patterns skill with guidelines on API design, database optimization, and server-side best practices.
- Added coding standards skill outlining universal coding principles for TypeScript, NestJS, and Node.js development.
- Implemented continuous learning skill to automatically extract reusable patterns from Cursor sessions.
- Created NestJS best practices skill detailing architecture patterns, dependency injection, error handling, and security measures.
- Included various rules and templates for NestJS best practices to ensure production-ready applications.

.cursor/contexts/dev.md

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+# Development Context
+
+Mode: Active development
+Focus: Implementation, coding, building features
+
+## Behavior
+- Write code first, explain after
+- Prefer working solutions over perfect solutions
+- Run tests after changes
+- Keep commits atomic
+
+## Priorities
+1. Get it working
+2. Get it right
+3. Get it clean
+
+## Tools to favor
+- Edit, Write for code changes
+- Bash for running tests/builds
+- Grep, Glob for finding code