#5228: Enhance error messages with recovery guidance

## Summary - Add categorized recovery metadata with suggestions + docs links - Show recovery guidance in TUI error output - Render structured error callouts in dashboard views (chat/overview/logs/channels) ## Testing - [ ] Untested - [ ] Lightly tested - [x] Fully tested Notes: Attempted to run tests, but they failed because dependencies were not installed and Node version was below required (>=22.12.0). ## AI Assistance - This PR was AI-assisted. - I confirm I understand the changes and their effects. ## Prompts / Session Notes - Implement categorized error system + recovery suggestions - Add docs links + user-friendly error display in TUI and dashboard <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Added categorized error recovery system with user-friendly guidance and docs links. Errors are now classified into 12 categories (auth, billing, rate_limit, timeout, etc.), each with tailored recovery suggestions and documentation links. The enhanced error display is integrated across TUI (terminal) and dashboard views (chat, overview, logs, channels). **Key changes:** - New `error-recovery.ts` (backend) and `recovery.ts` (frontend) modules categorize errors and provide recovery metadata - TUI error formatting enhanced with `formatRecoveryAssistantErrorText` showing title, suggestions, and docs links - Dashboard views now render structured error callouts via new `error-callout.ts` component - All referenced documentation paths exist and are valid <h3>Confidence Score: 4/5</h3> - Safe to merge with minor maintenance consideration - Well-structured feature addition with consistent patterns. One style concern about code duplication between backend/frontend error classification that could lead to maintenance issues over time. - ui/src/ui/errors/recovery.ts duplicates logic from src/infra/error-recovery.ts <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} <!-- /greptile_comment -->