CTX7-2817: Add Search API command to CLI

[fahreddinozcan]

Summary

• add ctx7 search for one-request documentation search
• support repeated --library hints, --version, --language, and --json
• use the existing authenticated CLI request headers and token refresh flow
• preserve Git Bash recovery for exact Context7 library IDs
• share documentation request parsing with ctx7 docs and keep Search response types separate
• keep library IDs required on Search snippets and preserve optional rules
• add command, request, and validation tests plus a minor changeset

Validation

• pnpm --filter ctx7 test
• pnpm --filter ctx7 typecheck
• pnpm --filter ctx7 lint:check
• pnpm --filter ctx7 build

All 379 CLI tests pass.

Dependency

This command calls the endpoint introduced by https://github.com/upstash/context7app/pull/1163.

[linear-code]

CTX7-2817