Backlog: H8 done a88bcedb088b

- [x] H5 Diff view: split (side by side) toggle remembered per user, collapse per file, hide whitespace changes, intra-line word highlighting.

- [x] H6 Forks: fork button, fork creation (store copy, forked_from), fork list, "propose to upstream" from a fork.

- [x] H7 Stars and watch counts, explore sorting (activity, stars, name) and filtering, repository topics.

- [ ] H9 File view: file tree sidebar, `y` for a permalink to the state, line range copy, blame age shading and "blame the state before this change".

- [ ] H10 Compare page with bookmark and tag pickers and a "propose this" button.

- [ ] H11 Help pages: getting started (install oxy, clone, push, tokens, CA, delegating to the hub), keyboard shortcuts, glossary for people coming from GitHub.

- 2026-09-28 O7 note: the O7 commit went in before clippy finished (two lints in the new help test); fixed in the next commit. The gate now runs to completion before every commit.

- 2026-09-28 H7 done: stars (toggle, counts), watcher counts on the overview, repository topics in settings (validated) shown as chips, Explore filter by text and topic and sort by activity/stars/name with per-row stars and topics; migration 0010. Tests: topic parsing unit test and `stars_topics_and_explore`. Gate fully green before commit; deployed.

- 2026-09-28 O8 done. `oxy git verify GIT_DIR` checks an import commit by commit (content, exec bits, symlinks, pins; conflicts named with their changes; first differing line). On a scratch mirror of tetriblox (539 commits, 208 merges, 880 gitlinks; the live repo was only read by `git clone --mirror`): import 36 s, tip tree round-trips exactly, and verification found **real core bugs that also affect ordinary commits**, now fixed: (1) insert after a line, then delete that line, left a delete/insert conflict (deletions now depend on the inserters of the lines right after them); (2) a binary or submodule reverted to an earlier blob lost it, and replacements had no dependency (now depend on the change that set their old blob; causal supersession, legacy records keep the old rule); (3) merges of independently replaced binaries/submodules stayed conflicted (importer resolves to the merge's blob). Mismatching commits went from 50+ (verification stopped early) to 5, now O11. Tests: 3 regressions (sequential insert/delete, binary revert, Git binary merge + verify). Spec Draft 0.8i §8.1, §9.3, §23. Hub redeployed.