feat: Effect services + HttpApi implementation + kit entry/CLI/dev server

- RomConfig/RomCache on the kit's ConfigService/CacheStore; RomSync wires the
  pure domain into the kit SyncEngine (poll/watch/coalesce/fingerprint) and
  ProviderClient; EngineStatus assembly shared by REST + SSE
- makeApi: HttpApiBuilder groups over live service values (handler runtime
  shares the plugin runtime's singletons) + sseRoute status feed
- index.ts: definePluginKit entry (async-main boundary); headless-first (UI
  serve failure logged, engine continues)
- cli.ts on the kit dispatcher: scan/detect/preview offline, sync/uninstall
  online; set-password is gone with the standalone server
- dev.ts: auth-free loopback API server (:5885) — the dev:live proxy target;
  never bundled
- verified live host-less: raw config round-trip on disk, status/platforms/
  preview endpoints, soft-fail reconcile without a host
- CI: workspace install, per-package typecheck, publish from plugin/

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

contract/src/domain.ts

@@ -2,7 +2,8 @@
 // the derived types keep the original domain names so the pure core reads unchanged.
 import { Schema } from "effect";
 
-export const Os = Schema.Literals(["linux", "windows", "mac"]);
+/** Host OS as the launch/quoting domain sees it (macOS hosts use the linux lane). */
+export const Os = Schema.Literals(["linux", "windows"]);
 export type Os = typeof Os.Type;
 
 /** Default emulator + core for a platform (operator-overridable per platform / per game). */
@@ -50,13 +51,13 @@ export const DetectedEmulator = Schema.Struct({
 	name: Schema.String,
 	template: Schema.String,
 	supportsArchives: Schema.Boolean,
-	contested: Schema.optionalKey(Schema.Boolean),
+	contested: Schema.optional(Schema.Boolean),
 	exeToken: Schema.String,
-	exePath: Schema.optionalKey(Schema.String),
-	appId: Schema.optionalKey(Schema.String),
+	exePath: Schema.optional(Schema.String),
+	appId: Schema.optional(Schema.String),
 	via: Schema.Literals(["path", "file", "flatpak"]),
-	coresDir: Schema.optionalKey(Schema.String),
-	cores: Schema.optionalKey(Schema.Array(Schema.String)),
+	coresDir: Schema.optional(Schema.String),
+	cores: Schema.optional(Schema.Array(Schema.String)),
 });
 export type DetectedEmulator = typeof DetectedEmulator.Type;
 
@@ -96,9 +97,9 @@ export const EngineStatus = Schema.Struct({
 	os: Os,
 	artProvider: Schema.NullOr(Schema.String),
 	syncing: Schema.Boolean,
-	lastSync: Schema.optionalKey(LastSync),
-	lastReport: Schema.optionalKey(SyncReport),
-	detectedAt: Schema.optionalKey(Schema.Number),
+	lastSync: Schema.optional(LastSync),
+	lastReport: Schema.optional(SyncReport),
+	detectedAt: Schema.optional(Schema.Number),
 	paths: Schema.Struct({
 		dir: Schema.String,
 		config: Schema.String,