docs(architecture): ADR-015 — manage grant tier + repo-op gate, OQ-16 identity namespace

Resolves review 001 finding A-1 (critical): ADR-012 §3's "scope
git:admin OR ownership" gate is not expressible in alkcall's
AccessControl (AND-composition). Resolution is the review's option (a)
shape with the OR-term generalized: the per-repo grant action set gains
manage, authorize(record, identity, read|write|manage) becomes the
single policy function for git access and repo administration, and the
delete/update/get gate is admin scope OR manage grant (handler-side,
generic FORBIDDEN, unknown-repo = unauthorized per ADR-008). Repo
create seeds the creator's {read, write, manage} grants —
administration is grantable, so collaborators/bots/app-compiled roles
work without global scopes. Ownership stays as alkcall spawn-tracking
(mint at create unchanged); "ownership never implies git access" is
superseded.

- ADR-015 (new): manage grant tier, op gate, flat-grants-as-replication-
  substrate, opaque grant-key rule
- ADR-011: action set + policy domain amended, references updated
- ADR-012 §3: gate table replaced, two-tier paragraph superseded
- backend.md/doors.md/overview.md: gate + grant restatements, ADR tables
- OQ-16 (new, deferred(scope)): grant-key identity namespace —
  globally-comparable ids for cross-assembly/replicator grant state;
  tracker task tasks/architecture/oq-16-grant-identity-namespace.md
- review 001: A-1 marked resolved (ADR-015)
- vision.md: supersession notes (Internal-ops framing, v1 grant set)

Verification: cargo test, clippy -D warnings, fmt --check, doc --no-deps
all clean.

docs/architecture/overview.md

@@ -88,22 +88,28 @@ multi-round negotiation are design-complete against real-client captures
 | [008](decisions/008-registry-resolved-repo-identity.md) | Repo identity | wire names are registry IDs |
 | [009](decisions/009-bounded-resources-budget.md) | Budgets | every session carries limits |
 | [010](decisions/010-pure-protocol-crate.md) | Pure protocol crate | single crate, producer/consumer halves, no doors/binary |
-| [011](decisions/011-per-repo-authorization.md) | Per-repo authorization | grants in repo records, policy in core, vault-nil |
+| [011](decisions/011-per-repo-authorization.md) | Per-repo authorization | grants in repo records, policy in core, vault-nil (amended: ADR-015) |
 | [012](decisions/012-registry-backing-and-ops.md) | Registry + ops | read/write split, file default, CRUD ops, feature split |
 | [013](decisions/013-receive-pack-state-machine.md) | receive-pack | V0-framed push machine, thin-pack acceptance, unpack-first CAS |
 | [014](decisions/014-v2-negotiation-ack-loop.md) | Negotiation | ack loop, `common_haves` seam, no `ready` |
+| [015](decisions/015-manage-grant-and-op-gate.md) | Manage grant + op gate | `manage` tier, admin-OR-manage gate, create seeds manage |
+| [015](decisions/015-manage-grant-and-op-gate.md) | Manage grant + op gate | `manage` tier, admin-OR-manage gate, create seeds manage |
 
 ## Open Questions
 
 Key questions tracked in [open-questions.md](open-questions.md):
 
 - **OQ-03**: publish-time API freeze inventory (the `git/repo/*` op set
-  and the trait family enter it; ADR-012, ADR-013/014's trait additions).
+  and the trait family enter it; ADR-012, ADR-013/014's trait additions;
+  the ADR-015 three-action grant shape must land in it).
 - **OQ-05**: sha256 policy (deferred(scope), low).
+- **OQ-16**: grant-key identity namespace (deferred(scope); blocks
+  nothing in v1 — ADR-015 §7).
 
 Resolved this cycle: OQ-04 (ADR-013 — receive-pack state machine,
 capture-grounded), OQ-02 (ADR-014 — negotiation ack loop). Earlier:
 OQ-08 (ADR-011 — per-repo authorization, grants in records, vault-nil),
 OQ-06 (ADR-012 — `registry-file` default, persistence adapters
-additive), OQ-07 (ADR-012 — CRUD ops shipped External with
-scope+ownership ACL), OQ-09/OQ-01 (ADR-010 — pure protocol crate).
+additive), OQ-07 (ADR-012 — CRUD ops shipped External with scope+grant
+ACL, gate amended by ADR-015), OQ-09/OQ-01 (ADR-010 — pure protocol
+crate).