Merge branch 'main' into ragnorc/omnigraph-mcp-crate

Folds in v0.7.2 (release #301) + RFC-013 Phase 7 (graph lineage in __manifest,
internal schema v3→v4 migration #299; WriteTxn #298; recovery convergence #296)
under the MCP branch.

Conflict resolutions (2 files):
- crates/omnigraph-server/Cargo.toml: take main's 0.7.2 path-dep constraints;
  keep our omnigraph-mcp dep (bumped to 0.7.2).
- docs/releases/v0.8.0.md (add/add): both branches drafted v0.8.0 notes for the
  same next minor — combined them. v0.8.0 now documents BOTH the MCP surface
  (ours) and main's __manifest lineage fold + the breaking internal-schema-v4
  upgrade-order requirement (kept prominent under Upgrade notes). Corrected our
  'no breaking changes / on-disk format unchanged' line, which the v4 migration
  makes false.

Coherence: omnigraph-mcp [package] + Cargo.lock bumped 0.7.1→0.7.2; openapi.json
auto-merged to info.version 0.7.2 (no API-surface drift from the incoming
engine-internal commits). Verification deferred to CI (no local rebuild).

AGENTS.md

@@ -16,7 +16,7 @@ Tools that support `@`-imports (Claude Code) auto-include all three files via th
 
 `CLAUDE.md` is a symlink to this file — there is exactly one source of truth. Edit `AGENTS.md`.
 
-**Version surveyed:** 0.7.1
+**Version surveyed:** 0.7.2
 **Workspace crates:** `omnigraph-compiler`, `omnigraph` (engine), `omnigraph-policy`, `omnigraph-api-types` (shared HTTP wire DTOs), `omnigraph-cluster`, `omnigraph-cli`, `omnigraph-server`
 **Storage substrate:** Lance 7.x (columnar, versioned, branchable)
 **License:** MIT
@@ -264,7 +264,7 @@ omnigraph policy explain --cluster ./company-brain --graph knowledge --actor act
 | Schema language | — | `.pg` + Pest grammar + catalog + interfaces + constraints + annotations |
 | Query language | — | `.gq` + Pest grammar + IR + lowering + linter |
 | Schema migration planning | — | `plan_schema_migration` + `apply_schema` step types + `__schema_apply_lock__` |
-| Commit graph (DAG) across whole graph | — | `_graph_commits.lance` with linear + merge parents, ULID ids, actor map |
+| Commit graph (DAG) across whole graph | — | Lineage (linear + merge parents, ULID ids, actor) stored as `graph_commit`/`graph_head` rows in `__manifest`, written in the same publish CAS as the table-version rows (RFC-013 Phase 7 — no separate `_graph_commits.lance` write; manifest→commit-graph atomicity gap closed); the in-memory commit graph is a projection of those rows |
 | Per-query atomic writes | — | In-memory `MutationStaging.pending` accumulator + `stage_*` / `commit_staged` per touched table at end-of-query + publisher CAS via `commit_with_expected` (single manifest commit per `mutate_as` / `load`); D₂ parse-time rule keeps inserts/updates and deletes from mixing |
 | Three-way row-level merge | — | `OrderedTableCursor` + `StagedTableWriter`, structured `MergeConflictKind` |
 | Change feeds | — | `diff_between` / `diff_commits` with manifest fast path + ID streaming |