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/tail-events.ts

@@ -1,12 +1,17 @@
-// Tail the host's lifecycle events — the SDK "hello world" (Promise facade).
+// ── Example 1/4 · the "hello world" ─────────────────────────────────────────────────────────
+// Connect, make one typed API call, and tail the host's lifecycle events. No Effect knowledge
+// needed — `connect()` returns a plain Promise client.
 //
 //   bun examples/tail-events.ts          (on the host box: zero config)
 //   PUNKTFUNK_MGMT_URL=… PUNKTFUNK_MGMT_TOKEN=… bun examples/tail-events.ts
 import { connect } from "../src/index.js";
 
 const pf = await connect();
-const host = (await pf.request("GET", "/host")) as { hostname?: string };
-console.log(`connected to ${host.hostname ?? "host"} — tailing events (^C to stop)`);
+
+// `pf.api.*` is the typed front door: `host` is a fully-typed HostInfo — no cast, autocomplete
+// for every field.
+const host = await pf.api.getHostInfo();
+console.log(`connected to ${host.hostname} — tailing events (^C to stop)`);
 
 pf.events.on("*", (e) => console.log(`[${e.seq}] ${e.kind}`, JSON.stringify(e)));
 pf.events.on("unknown", (e) => console.log("[unknown kind]", JSON.stringify(e)));