feat(sdk): Effect v4 + @effect/openapi-generator; typed pf.api & example ladder

Drop Orval for the first-party @effect/openapi-generator (OpenAPI 3.1 ->
Effect Schema + a typed HttpClient client) and bump effect 3.19 ->
4.0.0-beta.98. Port the hand-written surfaces to the v4 API (Result over
Either, Context.Service, Codec, Literals/Union arrays, Stream/Schedule/
Effect renames). Transport (CA-pinning fetch) and the reconnecting SSE
source are kept intact.

Make the SDK approachable for non-Effect users:
- Add pf.api.* on the Promise facade: the generated client surfaced as
  typed, Promise-native methods (await pf.api.listPairedClients()), so REST
  calls are autocompleted and checked instead of stringly-typed
  pf.request(method, path, body) + `as` casts. Zero-drift veneer over
  make(httpClient), backed by the same pinning fetch. pf.request stays as
  the untyped escape hatch.
- Re-tier examples into a 1-4 complexity ladder, rewritten onto pf.api.*
  (the typed payloads caught a wrong `launch` shape in provider-sync);
  the Effect example is labelled advanced. Add examples/ to tsconfig so
  they are typechecked (stops rot).

typecheck + 19 tests green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

sdk/examples/couch-preset.effect.ts

@@ -1,6 +1,11 @@
-// The RFC §7 quickstart, Effect-native: when the living-room TV starts a stream, apply a
-// display preset — a composed, typed, interruptible program.
-import { Effect, Stream } from "effect";
+// ── Example 4/4 · ADVANCED, Effect-native ───────────────────────────────────────────────────
+// You do NOT need this to use the SDK — examples 1–3 (the plain Promise `connect()` facade) cover
+// most automation. Reach for `@punktfunk/host/effect` only when you're composing Effect programs
+// and want the event stream, typed errors, and structured interruption as first-class values.
+//
+// Here: when the living-room TV starts a stream, apply a display preset — as a single composed,
+// typed, interruptible program (a `Stream` of events piped into a request, provided a live layer).
+import { Cause, Effect, Stream } from "effect";
 import { events, PunktfunkHost, PunktfunkHostLive } from "../src/effect.js";
 
 const program = Effect.gen(function* () {
@@ -12,7 +17,11 @@ const program = Effect.gen(function* () {
 		Stream.runForEach(() =>
 			pf
 				.request("PUT", "/display/settings", { mode: "preset", preset: "couch" })
-				.pipe(Effect.catchAll((e) => Effect.logWarning(`preset failed: ${e}`))),
+				.pipe(
+					Effect.catchCause((cause) =>
+						Effect.logWarning(`preset failed: ${Cause.pretty(cause)}`),
+					),
+				),
 		),
 	);
 });