[WIP] Add models command for OpenRouter model search and selection

[Copilot]

• Fix model name in OpenRouter-minimax template (minimax-m1-80k vs minimax-m2.1)
• Add cache expiration mechanism for model cache
• Consider unifying searchModelsInteractive and selectModelInteractive
• Add test coverage for models command
• Fix displayName for OpenRouter template (remove specific model from name)
• Restore removed provider templates (if unintentional)
• Remove duplicate OpenRouterModel interface - import from models.ts
• Remove duplicate formatContext function - extract to shared utility
• Add validation for manually entered model IDs
• Improve OpenRouter detection logic with proper URL parsing
• Add NaN validation for parseFloat operations on pricing
• Add fallback handling for undefined model selection
• Add NaN validation for parseInt on options.limit

---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[Copilot]

Copilot wasn't able to review any files in this pull request.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.