Review (PR #132) caught a regression: removing __run__ from
`is_internal_system_branch` exposed legacy `__run__*` branches to the
schema-apply blocking-branch checks (schema_apply.rs:104 and :778) and to
`branch_list()`, but the v2→v3 sweep ran only inside the publisher's
`load_publish_state`. On a pre-v0.4.0 graph whose first write is a schema
apply, the blocking-branch check fires before any publish, so apply failed
with "found non-main branches: __run__…". The same lazy timing also created a
reverse hazard: a user-created `__run__*` branch on a still-v2 graph could be
deleted by the first publish's sweep.
Fix: run the internal-schema migration in `Omnigraph::open(ReadWrite)` (new
`manifest::migrate_on_open`), before the coordinator reads branch state. The
sweep now lands before any branch-observing code, and a graph is stamped v3 at
open — so the one-time sweep can never catch a legitimately-created branch.
Both checks and `branch_list` see the swept graph; correct by construction for
every write path.
Accepted residual: a read-only open of an unmigrated legacy graph still lists
`__run__*` (read-only opens must not write, so they can't sweep). Documented.
Regression test `legacy_run_branch_is_swept_on_open_and_does_not_block_schema_apply`
confirmed RED before the fix (panicked on the branch_list leak assertion) and
GREEN after. Also updates the stale schema_apply.rs comment, the writes.md
"Migration code" section, and adds the v3 row to storage.md's migration table.
With the v2→v3 migration sweeping stale `__run__*` branches off `__manifest`
on first read-write open, the defense-in-depth `is_internal_run_branch` guard
is no longer needed.
- delete `db/run_registry.rs`; drop the module + re-export from `db/mod.rs`
- collapse `is_internal_system_branch` to the schema-apply-lock check only
- `ensure_public_branch_ref`: drop the run-ref rejection; `__run__*` is now an
ordinary branch name
- `branch_merge`: reject `is_internal_system_branch` (was run-only) so the
schema-apply lock is rejected consistently with create/delete — a small,
deliberate tightening
- update the inline schema-apply test + the writes integration tests
(`public_branch_apis_reject_internal_run_refs` →
`public_branch_apis_reject_internal_system_refs`, which also asserts
`__run__*` now creates successfully)
- docs: flip the "pending production sweep / defense-in-depth" notes to
"auto-swept by the v2→v3 migration"; document the read-only-open limitation
Known residual: the inert `_graph_runs.lance` / `_graph_run_actors.lance` bytes
remain until a `StorageAdapter::delete_prefix` primitive lands.
