refactor(cli): centralize settings and modernize ESM module system

[nicknisi]

Summary

This PR modernizes the CLI package with a centralized configuration system and full ESM compliance. The changes reduce code duplication, improve maintainability, and remove unused legacy code.

Centralized Settings System

• New settings.json - Single source of truth for all CLI configuration including:
  • API URLs (WorkOS, dashboard) with dev/prod variants
  • Framework-specific settings (ports, callback paths)
  • Telemetry configuration
  • Logging settings
  • Documentation URLs
  • Branding (ASCII art)
• New settings.ts - Type-safe accessor with full TypeScript interface
• Refactored constants.ts - Now derives values from settings instead of hardcoding

ESM Modernization

• Switched from node16 to nodenext module resolution
• Added explicit .js extensions to all relative imports
• Updated to ESM-native chalk@5.4.1 (from CJS chalk@2.4.1)
• Enabled resolveJsonModule with import attributes (with { type: 'json' })
• Added "type": "module" to package.json
• Replaced CJS __dirname pattern with import.meta.url

Removed Legacy Code

• Deleted query.ts - Unused LLM query system (99 lines)
• Removed CloudRegion and AIModel types - No longer needed
• Removed region-specific URL functions - getHostFromRegion, getCloudUrlFromRegion, getOauthClientIdFromRegion
• Removed unused agentResult variable from agent runner

Code Quality Improvements

• Replaced console.error with debug() for consistent error logging
• Added node: protocol prefix to built-in module imports in tests
• Prefixed unused parameters with underscore (_apiKey)
• Simplified clack-utils.ts with cleaner control flow
• Fixed terminal width detection (process.stdout.columns guard)

Files Changed

Category	Files
New	settings.json, src/lib/settings.ts
Deleted	src/utils/query.ts
Core refactors	constants.ts, urls.ts, debug.ts, bin.ts
ESM imports	25+ files updated with .js extensions
Config	tsconfig.json, package.json

[nicknisi]