feat: rename ALPN prefix from alknet/ to alk/ (v0.1.1)

- CHANNELS_ALPN: b"alknet/channels" → b"alk/channels"
- CallAdapter::alpn(): b"alknet/call" → b"alk/call"
- derive_alpn_from_op_name: alknet/ prefix → alk/ prefix
- All ALPN string literals in src/ and docs/ updated
- ADR-004 amended with prefix rename rationale
- AGENTS.md, README.md updated
- Version bumped to 0.1.1

Review: docs/reviews/003-alpn-prefix-rename.md

Verification:
- cargo test: 542 passed, 0 failed
- cargo clippy --all-targets -- -D warnings: clean
- cargo fmt --check: clean
- cargo doc --no-deps: clean

docs/architecture/call-protocol.md

@@ -5,13 +5,13 @@ last_updated: 2026-07-09
 
 # Call Protocol
 
-The wire protocol, stream model, framing, and adapter that alknet-call implements on ALPN `alknet/call`.
+The wire protocol, stream model, framing, and adapter that alknet-call implements on ALPN `alk/call`.
 
 ## What
 
-The call protocol is a bidirectional, transport-agnostic RPC protocol that runs over any ordered, reliable bidirectional stream within a single `alknet/call` connection. It supports request/response calls, streaming subscriptions, batch operations, and service discovery — all using the same EventEnvelope wire format.
+The call protocol is a bidirectional, transport-agnostic RPC protocol that runs over any ordered, reliable bidirectional stream within a single `alk/call` connection. It supports request/response calls, streaming subscriptions, batch operations, and service discovery — all using the same EventEnvelope wire format.
 
-The `CallAdapter` implements `ProtocolHandler` for ALPN `alknet/call`. It receives a `Connection` from the endpoint (QUIC-native, or TCP+TLS/WebTransport/SSH via `Connection::from_stream` — ADR-007), accepts bidirectional streams, and dispatches incoming `EventEnvelope` messages to the operation registry.
+The `CallAdapter` implements `ProtocolHandler` for ALPN `alk/call`. It receives a `Connection` from the endpoint (QUIC-native, or TCP+TLS/WebTransport/SSH via `Connection::from_stream` — ADR-007), accepts bidirectional streams, and dispatches incoming `EventEnvelope` messages to the operation registry.
 
 ## Why
 
@@ -104,13 +104,13 @@ below.
 
 ### CallConnection
 
-A `CallConnection` represents an established `alknet/call` connection,
+A `CallConnection` represents an established `alk/call` connection,
 regardless of which side opened it (ADR-022). It holds the connection's
 imported-ops overlay (Layer 2, ADR-019) — the set of `from_call`-imported
 operations discovered when the connection was established.
 
 ```rust
-/// An established alknet/call connection (either direction — accepted or
+/// An established alk/call connection (either direction — accepted or
 /// opened). Holds the connection's Layer 2 overlay (imported ops).
 pub struct CallConnection {
     /// The underlying transport Connection (from endpoint.accept,
@@ -197,7 +197,7 @@ The call protocol uses bidirectional streams with EventEnvelope framing (transpo
 - **Either side can open streams**: The client opens a stream to call a server operation. The server opens a stream to call a client operation. Both use `open_bi()` and `accept_bi()`.
 - **Correlation by request ID**: The `id` field in `EventEnvelope` correlates requests with responses. A response arriving on stream N can fulfill a request sent on stream M. The `PendingRequestMap` is keyed by ID, not by stream.
 - **Stream usage is the client's choice**: A client may open one stream per operation, one stream for all operations, or any mix. The server processes EventEnvelopes regardless of stream origin.
-- **One connection, full access**: A single `alknet/call` connection provides access to all operations (call, subscribe, batch, schema). No need for multiple connections or multiple ALPNs.
+- **One connection, full access**: A single `alk/call` connection provides access to all operations (call, subscribe, batch, schema). No need for multiple connections or multiple ALPNs.
 
 ### Wire Format: EventEnvelope
 
@@ -569,7 +569,7 @@ Handlers clean up resources when their call is cancelled (in Rust, the future is
 |----------|-----|---------|
 | Hand-rolled EventEnvelope framing (irpc never integrated) | [ADR-014](decisions/064-irpc-never-integrated-hand-rolled-framing.md) | Hand-rolled length-prefixed JSON framing, operation registry, dispatch; supersedes ADR-013 (irpc was never imported) |
 | Call protocol stream model | [ADR-015](decisions/012-call-protocol-stream-model.md) | Bidirectional streams, EventEnvelope, ID-based correlation |
-| ALPN per connection | [ADR-004](decisions/006-alpn-convention-and-connection-model.md) | `alknet/call` is a distinct ALPN, one connection per ALPN |
+| ALPN per connection | [ADR-004](decisions/006-alpn-convention-and-connection-model.md) | `alk/call` is a distinct ALPN, one connection per ALPN |
 | ProtocolHandler receives Connection | [ADR-005](decisions/007-bistream-type-definition.md) | CallAdapter gets Connection, can accept/open multiple streams |
 | Vault integration point | [ADR-008](decisions/008-secret-service-integration.md) | Vault is a capability source, accessed at assembly time |
 | Secret material flow | [ADR-010](decisions/014-secret-material-flow-and-capability-injection.md) | Call protocol carries no secret material; capabilities injected at assembly layer |