build: PaddedCell-style install.mjs + SDK-aligned packaging

install.mjs (--install/--build-only/--uninstall/--openclaw-profile-path),
tsconfig outDir dist/fabric, package.json openclaw file dep + main.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

node_modules/engine.io-client/build/esm/util.d.ts

@@ -0,0 +1,7 @@
+export declare function pick(obj: any, ...attr: any[]): any;
+export declare function installTimerFunctions(obj: any, opts: any): void;
+export declare function byteLength(obj: any): number;
+/**
+ * Generates a random 8-characters string.
+ */
+export declare function randomString(): string;