docs: ADR-049/050 in indexes; changelog link refs; ported-ADR range 001..048

- architecture README: index rows for ADR-049 (establishment phase) and
  ADR-050 (pump_bidi); stale ADR-001..045 range labels corrected
- channel-operations.md: design-decision table + references list the
  two new ADRs
- CHANGELOG: missing link references for 0.4.0/0.4.1/0.5.0/0.6.0
- AGENTS.md: ADR range 001..050

docs/architecture/README.md

@@ -13,7 +13,7 @@ This crate unifies `alknet-call` and `alknet-channels` from the alknet
 mono-repo, plus the vendored core types formerly in `alknet-core`. The
 source architecture docs were ported from
 `/workspace/@alkdev/alknet/docs/architecture/` and renumbered as alkcall
-ADRs (ADR-001..045). The ALPN strings (`alk/call`, `alk/channels`)
+ADRs (ADR-001..050). The ALPN strings (`alk/call`, `alk/channels`)
 are wire-stable and unchanged — see ADR-004.
 
 ## Documents
@@ -101,6 +101,8 @@ are wire-stable and unchanged — see ADR-004.
 | [046](decisions/046-publish-operation-type-and-handler-kind-sink.md) | Publish Operation Type and HandlerKind::Sink | `OperationType::Pub` (producer→consumer streaming); `SinkHandler` + `HandlerKind::Sink`; `call.published` wire event; `invoke_sink()` dispatch; `Subscription` renamed to `Sub` |
 | [047](decisions/047-openable-alpns-are-operations.md) | Openable ALPNs Are Operations | `channel/open` dissolves into per-ALPN ops `channels/<alpn>/sub`/`pub`; `channel_open` marker on `OperationSpec`; `ChannelCore` wrapper; extension-trait `ChannelOperationEnv`; connection-owner allocates `channel_id`; opener ledger (Gap 2 fix); ALPNs are call apps |
 | [048](decisions/048-dispatch-spine-gateway-module.md) | Dispatch Spine (feature-gated `gateway` module) | `alkcall::gateway` behind the `gateway` feature; `GatewayDispatch` invoke spine (deadline knob, re-rooted context) + `schema_disclosure_denial` (FORBIDDEN for ACL deny, spec-404 for Internal); promoted from alkhttp for hub/spoke reuse |
+| [049](decisions/049-channel-open-establishment-phase.md) | Channel-Open Establishment Phase | `OpenEstablisher` + `register_openable_with_establisher` (awaited, bounded); typed `channel:open_failed` with `details.reason`; `Establishment.plan` (`ChannelPlan`) threaded to the `OpenHandler` (amendment 2); the `JoinHandle` data-plane lifetime contract |
+| [050](decisions/050-pump-bidi-two-pump-helper.md) | `pump_bidi` Two-Pump Helper | `channels::pump_bidi` — shutdown-on-completion two-pump data plane pinned in one place (alknet ADR-078) |
 
 ## Relevant Open Questions
 
@@ -272,7 +274,7 @@ feature flags) or in the downstream alknet crate.
 
 - `@alkdev/alknet: docs/architecture/` — the source architecture docs
   these were ported from (renumbered from alknet ADR-001..094 to alkcall
-  ADR-001..045)
+  ADR-001..048; ADR-049 and later were authored in this crate)
 - `@alkdev/alktype` — the binary struct engine; compiles BAST documents
   (e.g. `chunk-header.bast.json`) into readers/writers/validators
 - `@alkdev/pubsub` — the TypeScript EventEnvelope prior art the call
@@ -288,5 +290,5 @@ feature flags) or in the downstream alknet crate.
 > TTY's wire format, ADR-082 for alknet-tls, ADR-086 for endpoint types).
 > These are ADRs for sibling crates that are not part of alkcall. They
 > retain their alknet numbering (052, 082, 086, etc.) — any ADR number
-> outside the alkcall range 001..045 is an alknet source ADR, found at
+> outside the alkcall range 001..048 is an alknet source ADR, found at
 > `/workspace/@alkdev/alknet/docs/architecture/decisions/`.