feat(github-app): add repo command authorization policy

[mkdev5]

Summary

• Add repo-level command authorization policy settings for public @gittensory command handling.
• Preserve secure defaults: maintainers/collaborators can run commands, confirmed-miner PR authors can run normal own-PR commands, and queue-digest commands stay maintainer/collaborator only by default.
• Apply policy during issue_comment processing, include private preview diagnostics, and audit denied commands with normalized allowed roles.
• Closes feat(github-app): add repo-level command authorization policy #106.

Scope

• This PR is focused and does not mix unrelated backend, UI, MCP, docs, dependency, and deploy changes.
• This follows CONTRIBUTING.md and does not reintroduce GitHub Pages, VitePress, site/, or CNAME.
• I linked an issue, or this is small enough that the summary explains why an issue is not needed.

Validation

• git diff --check
• npm run actionlint
• npm run typecheck
• npm run test:coverage locally; global coverage stays at or above 97% for lines, statements, functions, and branches (aim for 98%+ branch coverage locally so CI variance does not fail near the threshold)
• npm run test:workers
• npm run build:mcp
• npm run test:mcp-pack
• npm run ui:openapi:check
• npm run ui:lint
• npm run ui:typecheck
• npm run ui:build
• npm audit --audit-level=moderate
• New or changed behavior has unit/integration tests for new branches, fallback paths, and sanitizer boundaries

If any required check was skipped, explain why:

• None. npm run test:ci passed locally. Coverage from the local run was statements 99.09%, branches 97.03%, functions 98.43%, and lines 99.66%.

Safety

• No secrets, wallet details, hotkeys, coldkeys, user PATs, private keys, raw trust scores, private rankings, or private maintainer evidence are exposed.
• Public GitHub text stays sanitized, low-noise, and does not imply compensation guarantees or optimization tactics.
• Auth, cookie, CORS, GitHub App, Cloudflare, or session changes include negative-path tests.
• API/OpenAPI/MCP behavior is updated and tested where needed.
• UI changes use live API data or real empty/error/loading states, not production mock/demo fallbacks.
• Visible UI changes include screenshots or a short recording.
• Public docs/changelogs are updated where needed; changelogs are only edited for release-prep PRs.

Notes

• No visible UI changes; the UI artifact change is the generated OpenAPI contract only.
• Adds migration 0020_command_authorization_policy.sql for the repository settings JSON policy column.
• Policy diagnostics stay in private API/settings-preview surfaces; public command comments remain sanitized and unchanged in shape.

[JSONbored]

@MkDev11 this is the one I would land first in the current migration stack.

A few notes:

• The repo command authorization policy is a concrete production guard, not a speculative helper.
• The migration follows current main cleanly as the next 0020 candidate.
• No code changes requested.

Validation expected:

• Keep the current green CI run after any required branch update.