Add public-safe showcase case set

[huangruiteng]

Summary

• update the showcase catalog and README appendix so the public repo now reflects all 7 current Showcase & Good Case rows
• add public-safe case pages for the 0623 agent-to-agent PR loop, 0623 overnight refactor, 0624 PR issue auto-fix loop, and 0627 overnight PR batch
• keep the four newly added cases as appendix surfaces, preserving the existing three canonical PoC cards as the first frontstage set

Evidence and Boundary

• Lark top table was updated and re-fetched at revision 1605 with 7 rows
• 0627 public repo signal is limited to reproducible Git history: 22 commits, 60 files, 6695 insertions, 223 deletions in the stated window
• private screenshots, raw chats, internal docs, local paths, credentials, and raw logs are explicitly excluded from the public case pages

Validation

• python3 -m json.tool docs/showcases/showcase-catalog.json
• python3 examples/showcase-catalog-smoke.py
• loopx check --scan-path docs/showcases/README.md --scan-path docs/showcases/showcase-catalog.json --scan-path docs/showcases/cases/0623-agent-to-agent-pr-comments.md --scan-path docs/showcases/cases/0623-overnight-project-refactor.md --scan-path docs/showcases/cases/0624-pr-issue-auto-fix.md --scan-path docs/showcases/cases/0627-overnight-pr-batch.md
• git diff --check

[huangruiteng]

Findings: none.

Open questions / assumptions: treated this as a docs-only showcase/catalog update. The four newly added cases are appendix-only public-safe surfaces; the existing three canonical PoC cards remain the first frontstage set.

Validation performed:

• python3 -m json.tool docs/showcases/showcase-catalog.json
• python3 examples/showcase-catalog-smoke.py
• loopx check --scan-path docs/showcases/README.md --scan-path docs/showcases/showcase-catalog.json --scan-path docs/showcases/cases/0623-agent-to-agent-pr-comments.md --scan-path docs/showcases/cases/0623-overnight-project-refactor.md --scan-path docs/showcases/cases/0624-pr-issue-auto-fix.md --scan-path docs/showcases/cases/0627-overnight-pr-batch.md
• git diff --check origin/main...HEAD
• GitHub Frontstage Pages / build passed

Merge decision: self-merge eligible under AGENTS small public-docs policy after validation and public/private boundary scan.

[huangruiteng]

Update: normal self-merge was blocked by the base branch policy, and repository auto-merge is disabled. I did not use admin bypass. Holding PR #745 for maintainer review/merge; local validation and GitHub build remain clean.

[huangruiteng]

Owner requested merging #745 first as the baseline for the follow-up showcase page/style work. Clean-head validation just rerun:\n- python3 -m json.tool docs/showcases/showcase-catalog.json\n- python3 examples/showcase-catalog-smoke.py\n- git diff --check origin/main...HEAD\n- loopx check public-boundary scan over changed showcase docs/catalog/case pages\n- GitHub Frontstage Pages / build is green\n\nGitHub does not allow this account to approve its own PR, so I am proceeding with maintainer/admin merge per the explicit owner request.