docs: implementation plan (TTY precedents folded in); task decomposition (17 tasks)

Plan updated with the alknet-tty findings: the drainer pattern
(single ordered writer) makes outbound chunk-boundary parsing sound;
TestStdinSink's try_send→Full→Pending is the inbound backpressure
precedent; OQ-01(a) now cites the reference.

Task graph (taskgraph-validated, 17 tasks, 6 generations, no cycles):
- tasks/server/: core-types, auth, healthz-decoy, adapter
- tasks/gateway/: dispatch, routes, publish
- tasks/websocket/: byte-adapter (research POC), upgrade-session, overlay-ops
- tasks/adapters/: from-openapi, from-jsonschema, to-openapi, from-wss, mcp
- tasks/client/: http-host
- tasks/infra/: integration-suite (phase 4)

Critical path runs through server core → adapter → WS session →
overlay tests → integration suite. High-risk tasks are the three WS
tasks, de-risked by the ws-byte-adapter POC blocking upgrade-session.

tasks/gateway/routes.md

@@ -0,0 +1,45 @@
+---
+id: gateway-routes
+name: The 5 core gateway routes wired into the router
+status: pending
+depends_on: [gateway-dispatch, server-adapter]
+scope: moderate
+risk: medium
+impact: component
+level: implementation
+tags: [gateway, phase-1]
+---
+
+## Description
+
+Port `server/gateway_routes.rs` from
+`/workspace/@alkdev/alknet/crates/alknet-http/src/server/gateway_routes.rs`:
+`GET /search` (AccessControl-filtered services/list), `GET /schema`,
+`POST /call` (`{operation, input}`), `POST /batch`, and `POST /subscribe`
+(SSE projection: `text/event-stream`, `call.responded` → `data:` frames,
+terminal error event, abort on client disconnect). Auth middleware
+applied to all five. The route set intentionally excludes `/publish`
+(separate task). Integration tests over DuplexStream: search filtering
+by identity scopes, call round-trip, subscribe stream of multiple
+events, batch correlation.
+
+## Acceptance Criteria
+
+- [ ] 5 routes ported and wired in server-adapter's router
+- [ ] SSE framing tests (multi-event, error-terminates, client-disconnect)
+- [ ] /search returns only ops the caller's identity can invoke
+- [ ] Full request→dispatch→response test over DuplexStream
+- [ ] `cargo test` passes
+
+## References
+
+- docs/architecture/http-server.md (§router list, §Streaming projection)
+- docs/architecture/decisions/042-openapi-gateway-pattern.md, 047-remove-direct-call-http-surface.md
+
+## Notes
+
+> Agent fills during implementation.
+
+## Summary
+
+> Agent fills on completion.