[Bug] Missing validation for PR-ready state before enabling PR workflow

Bug Description
When you hand over to Ultraplan, and a git repo is detected, the harness assumes a remote exists and just says "Waiting for PR" which is not possible. There needs to be better validation of whether the codebase and repo is PR ready before enabling the "PR as the response" workflow

Environment Info

• Platform: darwin
• Terminal: WarpTerminal
• Version: 2.1.119
• Feedback ID: 8354d405-568b-41df-9a66-93471b3d5e81

Errors

[{"error":"Error: NON-FATAL: Lock acquisition failed for /Users/brendon/.local/share/claude/versions/2.1.119 (expected in multi-process scenarios)\n    at mH6 (/$bunfs/root/src/entrypoints/cli.js:2736:2177)\n    at E$8 (/$bunfs/root/src/entrypoints/cli.js:2736:1257)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-04-27T09:21:11.338Z"}]