A connected account's repository picker leaves origins.ts for src/web/pages/origin-repos.ts #6337

For: src/web/pages/origins.ts is too big to read or to change without a conflict; originReposPage, originMirrorSubmit and the helpers only they use (origins.ts near 1365–end) is one concept and gets its own module, with no change in behaviour.

Done:

• [ ] src/web/pages/origin-repos.ts holds originReposPage, originMirrorSubmit and the helpers only they use (origins.ts near 1365–end); src/web/pages/origins.ts keeps none of it and imports or calls it from the new file.
• [ ] Every route, page and form answers exactly as before: picking and mirroring a repository from a connected account answers as before; the origins and migrate tests pass unchanged.
• [ ] A helper both files need is exported from where it lives now; nothing is copied.
• [ ] Before pushing: bun x tsc --noEmit, the tests that cover the moved code, and bun scripts/design-lint.ts when src/web/ changes. A red test elsewhere that main also has is named in the pull.

Files: src/web/pages/origins.ts, src/web/pages/origin-repos.ts, the files that import what moved.

Risk: #6309 moves the connect flow out of origins.ts at the same time, and #6228 reworks /migrate; keep to your own lines.

Parked by the steward, 2026-10-26 (owner: "get us unclogged now then resume everything else"). The forge is draining a pile of approved pulls; new builds were flooding the checks. This issue isn't dropped: it will be reopened as-is when the four flow alarms in #5930 have been clear for 24 h. The list is kept in the steward's parked-2026-10-26 file.