[Feature Request] Add directory validation for GitHub project context in `/ultrareview` command

Bug Description
/ultrareview used the wrong GH project and hence could not find the branch [Image #1] It was my fault as was in the wrong directory - it would had been nice if this mistake would have been detected beforehand

Environment Info

• Platform: darwin
• Terminal: intellij
• Version: 2.1.112
• Feedback ID: 7581c1fd-5b3f-46bf-b18b-8a117274b322

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/johannes/.local/share/claude/versions/2.1.112 (expected in multi-process scenarios)\n    at Od_ (/$bunfs/root/src/entrypoints/cli.js:2748:2177)\n    at Ke6 (/$bunfs/root/src/entrypoints/cli.js:2748:1257)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-16T21:01:23.795Z"},{"error":"Error: Plugin MCP server error - mcp-config-invalid: MCP server greptile invalid: Missing environment variables: GREPTILE_API_KEY\n    at djH (/$bunfs/root/src/entrypoints/cli.js:2748:30115)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-16T21:01:23.809Z"}]

As /ultrareview returned with an empty result I would expect to not count down the actual /ultrareview count

⏺ The ultrareview completed but produced empty output. PR #289 doesn't exist in xxx/yyy — the repo's highest PR number is 8, and the current branch <branchname> has no open PR. The review likely failed
  silently because the target PR couldn't be found.                                                                                                                                                                                      
                                                                                                                                                                                                                                         
  Did you mean a different PR number, or would you like me to open a PR for this branch first?