Fix gallery proposal issue handoff

[Jay Gordon (jaydestro)]

Summary

• publish validated gallery recommendations as an editable, unassigned GitHub issue
• make every addition, URL update, and retirement identify its catalog operation and supporting information
• require explicit operator editing and agent assignment before any draft pull request is created
• fix issue publication from a checkout-free job by passing the repository explicitly to gh issue create
• align contributor documentation with the issue-first workflow

Validation

• npm run test:gallery-audit (60 tests passed)
• npm run build
• git diff --check

Context

Fixes the failure in Actions job 109462156835 from run 36584806162, where gh issue create could not infer a repository because the trusted publisher intentionally does not check out repository contents.