Docs: bookmarks in the guide, spec status table, plan fbda43e7d8ed

rewrites, and a content hash (`#7469d16c…`) that changes when the change is

edited. Use whichever you have; prefixes work.

## 4. Fix up history

Oxygen keeps its own record of every operation, so all of these are safe to

Rules as above. Spec Draft 0.8 defines each item; implement in this order, each with tests, a gate, and an oxy commit.

- [ ] Subrepositories (spec §7.8, §23): node kind `subrepo`, pin encoding, `.oxymodules`, snapshot stops at nested repositories and reads their pin, checkout moves or leaves nested repositories, `oxy submodule add|update|status|remove`; Git import/export of gitlinks and `.gitmodules` (test with a mirror of tetriblox, never the live repository).

- [ ] Partial commits (spec §12.3): `oxy commit PATH..` and `oxy commit --interactive` (hunk = one edit or tree operation, dependent hunks pulled in), sharing the split machinery.

- [ ] Blame (spec §27): `oxy blame PATH [--json]` from atom keys, with author and date; renames followed.

| Objects, hashing, deterministic CBOR (§5) | Implemented; format 2 repositories, migration from format 1 |

| Change graph, commutation, conflicts and resolution (§6–§9) | Implemented, including order, delete/insert, tree, replace, and mode conflicts; workspace conflicts (§9.7) and exit status 3 are not detected |

| Rewrites (§8.4) | Implemented: describe, amend (also into older changes), split, abandon; orphaned references re-anchored |

| Operation log, undo (§12.1) | Implemented; `redo` reserved |

| Snapshots and the stat cache (§12.3, §12.4) | Implemented; no file-system monitor yet |

| Storage: loose objects, packs, GC, checkpoints, batching (§11, §13, §21) | Implemented; pack indexes are read fully rather than mapped |