Backlog: V4 done f184f6d51a9f

- [x] V1 oxygenhub-vscode: proposal files in native diff editors (target state against projected state through a content provider), with review threads in them.

- [x] V2 oxygenhub-vscode: notifications count in the status bar and an inbox quick pick that opens the item.

- [x] V3 oxygenhub-vscode: completion of `#N` and `@user` in the Oxygen commit box and in comments; hover on `#N` shows the title.

- [ ] V5 oxygenhub-vscode: releases view; draft a release from a tag.

- [ ] V6 oxygen-vscode: history graph actions for split, squash and rebase (oxy history commands), with confirmation and undo hint.

- [ ] V7 oxygen-vscode: commit box polish: amend toggle, message history, signed/unsigned indicator, warning on conflict markers.

- 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.

- 2026-09-28 H8 done: open counts on the Proposals and Issues tabs (from the repository lookup), issue `author:` filter and sorts (newest/oldest/updated/comments), proposal filter (`author:`, `label:`, `target:`, words) with labels shown and sorts (updated/newest/oldest), 25-per-page pager keeping filter and sort. Test `lists_filter_sort_page_and_count`; spec §6.3 rows; deployed.

- 2026-09-28 O9 done: `portable::Platform` (detected, overridable in tests); no exec bits: snapshot keeps the recorded bit (it was recording a mode change on every Windows snapshot); no symlinks: a plain file holding the target stays the symlink (spec §7.7 required it, the code converted it); checkout lists case collisions and Windows-invalid names on affected platforms and `oxy doctor` does everywhere; CRLF already handled by the eol attribute; separators verified (components joined with /). Tests simulate Windows and macOS. Follow-up: normalise `\` in paths typed on Windows command lines. Spec §7.7. Hub redeployed.