[codex] PR_26175_ALFA_007 game hub project readonly proof

[ToolboxAid]

Summary

• Replaced the active BUILD_PR.md with PR_26175_ALFA_007 as the source of truth.
• Added a focused Playwright proof that existing Game Hub project/game identity is read-only outside the create row.
• Proves legacy Project Workspace panels are absent, source-idea child rows are read-only, source-linked delete is unavailable, and add/create is the editable new-name path.
• Added ALFA_007 report, validation lane, requirements checklist, changed-files report, review diff, and repo-structured delta ZIP metadata.

Validation

• PASS: npx playwright test tests/playwright/tools/GameHubMockRepository.spec.mjs --workers=1 --grep "Game Hub proves project identity is read-only outside create" ran 1 test: 1 passed, 0 failed.
• PASS: changed-source style scan found no inline style or style-block matches.
• PASS: git diff --cached --check before commit.

Notes

• No product UI files changed.
• No repository/API/service contract changes.
• Delta ZIP: tmp/PR_26175_ALFA_007-game-hub-project-readonly-proof_delta.zip.
• Commit: 6c7a25938e3b67ef969c815164733f7be7b94ede.

[ToolboxAid]

EOD cleanup: closing this draft as superseded by later merged work on main.

The ALFA_007 proof objective is now represented by current main via PR #130 / PR_26175_ALFA_008-game-hub-feature-matrix:

• docs_build/dev/reports/PR_26175_ALFA_008-game-hub-feature-matrix_report.md records PASS evidence for existing game names being read-only in edit mode, source idea child tables being read-only, source-linked projects being protected, and add/create remaining the editable new-name path.
• tests/playwright/tools/GameHubMockRepository.spec.mjs already covers the key read-only assertions in the broader Game Hub validation lane.

No merge is being attempted because this draft is old-base and not mergeable; its remaining report/test-specific delta is superseded by the later ALFA_008 audit/report merge.