docs(arch): sync call-completion specs with implementation — Dispatcher/RemoteFilter, ClientError, OQ-29

Post-implementation spec sync after the call-completion batch landed
(commits e4a2594..a3825f5). The sub-agent review flagged no spec drift, but
comparing the implemented types against the spec sketches surfaced five
details the specs didn't name — filled in here so the spec matches what was
built:

- client-and-adapters.md: name the shared Dispatcher (protocol/dispatch.rs)
  + RemoteFilter mechanism that enforces ADR-028's default-deny at dispatch
  time (the load-bearing security gate — checks remote_safe before building
  context, before any capability material reaches the handler). Add
  ClientError/RemoteIdentity types, the spawn_dispatch lower-level API, and
  the services_list_handler_peer_scoped wiring (the assembly layer must
  register the peer-scoped services/list handler for a CallClient's registry,
  not the plain one). Record the v1 TLS client-auth gap (AcceptAnyServerCertVerifier,
  with_no_client_auth) as OQ-29.
- call-protocol.md: point the adapter dispatch-loop description at the shared
  Dispatcher (dispatch.rs) so readers find the mechanism ADR-017 §1 commits to.
- open-questions.md: OQ-29 — CallClient TLS client-auth + remote-identity
  verification is a two-way-door remainder; the no-env-vars invariant is
  unaffected (auth_token flows via call-protocol payload, not TLS).
- READMEs: current-state now reflects completion done + reviewed (207 lib +
  2 integration tests); OQ-29 added to both OQ summaries.

docs/architecture/README.md

@@ -9,9 +9,9 @@ last_updated: 2026-06-26
 
 **Pre-implementation.** The project has completed a pivot from a three-layer model to an ALPN-as-service model. The greenfield workspace contains only `alknet-vault` (stable — implementation complete and verified, local-only by construction per ADR-025, HD-derivation key model per ADR-026) and research/reference material. Foundational ADRs (001–028) are in place. ADR-024 resolves the registry mutability question and the `OperationContext.env` type identity crisis by layering the registry by trust boundary. ADR-025 drops irpc from the vault, making it local-only by construction. ADR-026 records the HD-derivation key model as a foundational decision. Review #003 (type/API surface completeness) resolved: `DerivedKey` derive contradiction, `encrypt` prose, return-type divergence, RwLock contradiction, drift table gaps, ADR-022 stale sketches, `Capabilities`/`SessionOverlaySource`/`CallConnection`/`CachedKey` definitions, `CompositeOperationEnv` dispatch contract, `with_local` signature, payload schemas, timeout propagation, and request ID generation. The alknet-core and alknet-call crate specs are in draft; the alknet-vault crate specs are stable.
 
-The alknet-call server-side core (`CallAdapter`, `CallConnection` dispatch loop, wire framing, pending map, abort cascade, operation registry, service discovery) is implemented and tested (159 tests passing). The call-completion gap analysis (`docs/research/alknet-call-completion/gap-analysis.md`) identified the missing client/adapter surface specced in ADR-017 — `CallClient`, `from_call`, `from_jsonschema`, the `OperationAdapter` trait — plus four decisions (DC-1..4) needed before implementation. DC-1 (the one-way door: peer-scoped registry filtering) is resolved by ADR-028; DC-2/3/4 are two-way-door defaults recorded in `client-and-adapters.md` and tracked as OQ-25..28. The client/adapter surface is specced (`crates/call/client-and-adapters.md`); implementation is pending.
+The alknet-call crate is **implemented and reviewed** — both the server-side core and the client/adapter surface. The server-side core (`CallAdapter`, `CallConnection` dispatch loop, wire framing, pending map, abort cascade, operation registry, service discovery) and the client/adapter surface (`CallClient`, `from_call`, `from_jsonschema`, `OperationAdapter` trait, shared `Dispatcher`) are implemented and tested (207 lib + 2 integration tests passing). The call-completion gap analysis (`docs/research/alknet-call-completion/gap-analysis.md`) identified the missing client/adapter surface specced in ADR-017 plus four decisions (DC-1..4); all are resolved — DC-1 by ADR-028 (peer-scoped default-deny filtering), DC-2/3/4 as two-way-door defaults in `client-and-adapters.md` (OQ-25..28). A post-implementation review (`tasks/call/review-completion.md`) confirmed spec conformance; the one spec-sketch omission (`connect()`'s `ClientError` return type) was the intended illustrative-sketch gap, now filled in. A TLS client-auth gap surfaced during implementation is tracked as OQ-29.
 
-**Next step**: Implementation of the alknet-call client/adapter surface (priority order in `client-and-adapters.md`): `CallClient` → `from_call` → `OperationAdapter` trait → `from_jsonschema`. All one-way doors are resolved; remaining open questions (OQ-25..28) are two-way-door shape/defaults decided during implementation.
+**Next step**: The alknet-call crate is ready for downstream consumers (alknet-http's `OperationAdapter` implementations, the container-service/runner pattern, alknet-agent, alknet-napi). The remaining open questions (OQ-25..29) are all two-way-door shape/defaults, not blockers. The next crate phase is alknet-http (Phase 0 findings in `docs/research/alknet-http/`).
 
 ## Architecture Documents
 
@@ -102,6 +102,7 @@ See [open-questions.md](open-questions.md) for the full tracker.
 - **OQ-26**: `OperationAdapter` error type — `import()` returns `Result<_, AdapterError>`; variants decided in implementation
 - **OQ-27**: `from_call` re-import trigger — v1 default auto-on-reconnect; explicit `refresh()` additive
 - **OQ-28**: `from_call` namespace collision — v1 default error-on-collision (no prefix by default)
+- **OQ-29**: `CallClient` TLS client-auth + remote-identity verification — v1 connects with `with_no_client_auth()` and `AcceptAnyServerCertVerifier`; wiring RawKey client-auth is additive (the no-env-vars invariant is unaffected — `auth_token` flows through the call-protocol payload, not TLS)
 
 **Deferred (not active):**
 - **OQ-09**: WASM target boundaries — design constraint, not deliverable