docs(adrs): reconcile WS-03 browser data-channel promise (ADR-067/048)

Record the v1 cut for browser-opened data channels over WS (review-001
WS-03): the design (ADR-067) stands; only the wiring is deferred.

- open-questions.md: add OQ-05 (deferred(scope: v1 cut)) with gap
  detail and deferred scope
- ADR-067: dated status amendment + v1-cut note at the data-channel
  step; References point to OQ-05
- ADR-048: dated reconciliation note — overlay bidirectionality is
  decided design, not a v1 implementation commitment
- websocket.md: status notes on §"Data channels for browsers" and
  upgrade step 7
- task review-001-ws-data-channel-decision: completed, Summary filled

Verification: taskgraph validate (38 tasks OK); cargo doc --no-deps
(pre-existing warnings only).

docs/architecture/decisions/067-websocket-carries-channels.md

@@ -2,7 +2,8 @@
 
 ## Status
 
-Accepted
+Accepted (amended 2026-08-29 — the data-channel half of the WS path is
+deferred, not yet wired; see [OQ-05](../open-questions.md))
 
 ## Context
 
@@ -99,6 +100,13 @@ On upgrade, the handler:
    ops on channel 0 (alkcall ADR-047), the same mechanism as any
    consumer.
 
+> **v1 cut (2026-08-29):** step 4 is designed but not wired in v1 —
+> today the WS upgrade path installs channel 0 only and no
+> `register_openable`/data-channel dispatch path exists for browser
+> sessions (review-001, WS-03). The deferral and its rationale are
+> recorded in [OQ-05](../open-questions.md); the design above is the
+> contract the deferred wiring implements.
+
 Everything ADR-048 says about dispatch — `call.requested` →
 `Dispatcher::dispatch_requested` with `AccessControl::check` gating,
 `call.responded`/`call.completed`/`call.aborted` correlated by `id` via
@@ -158,7 +166,10 @@ in-line channels session:
 
 ## References
 
-- [websocket.md](../websocket.md) — the full WS session spec
+- [websocket.md](../websocket.md) — the full WS session spec (its
+  §"Data channels for browsers" carries the same v1-cut note)
+- [OQ-05](../open-questions.md) — the data-channel v1 cut deferral
+  (status `deferred(scope)`; reopened when a browser consumer lands)
 - [ADR-048](048-websocket-native-session-not-gateway.md) — the native
   session (not gateway shape) decision this ADR amends (channel 0
   framing; upgrade path)