fix: gateway install uses --@mosaic:registry flag to preserve npm prefix

Replace temp .npmrc + --userconfig approach with the --@mosaic:registry CLI
flag so the user's real ~/.npmrc (including prefix=/home/user/.npm-global)
is honoured. This eliminates EACCES errors for non-root installs that
relied on a user-level prefix config.

Bump @mosaic/cli and @mosaic/mosaic to 0.0.15.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/gateway/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaic/gateway",
-  "version": "0.0.3",
+  "version": "0.0.2",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaic/mosaic-stack.git",
@@ -28,8 +28,8 @@
   "dependencies": {
     "@anthropic-ai/sdk": "^0.80.0",
     "@fastify/helmet": "^13.0.2",
-    "@mariozechner/pi-ai": "^0.65.0",
+    "@mariozechner/pi-ai": "~0.57.1",
-    "@mariozechner/pi-coding-agent": "^0.65.0",
+    "@mariozechner/pi-coding-agent": "~0.57.1",
     "@modelcontextprotocol/sdk": "^1.27.1",
     "@mosaic/auth": "workspace:^",
     "@mosaic/brain": "workspace:^",
@@ -49,7 +49,7 @@
     "@nestjs/platform-socket.io": "^11.0.0",
     "@nestjs/throttler": "^6.5.0",
     "@nestjs/websockets": "^11.0.0",
-    "@opentelemetry/auto-instrumentations-node": "^0.72.0",
+    "@opentelemetry/auto-instrumentations-node": "^0.71.0",
     "@opentelemetry/exporter-metrics-otlp-http": "^0.213.0",
     "@opentelemetry/exporter-trace-otlp-http": "^0.213.0",
     "@opentelemetry/resources": "^2.6.0",

apps/gateway/src/agent/__tests__/provider-adapters.test.ts

@@ -62,7 +62,7 @@ function restoreEnv(saved: Map<EnvKey, string | undefined>): void {
 }
 
 function makeRegistry(): ModelRegistry {
-  return ModelRegistry.inMemory(AuthStorage.inMemory());
+  return new ModelRegistry(AuthStorage.inMemory());
 }
 
 // ---------------------------------------------------------------------------

apps/gateway/src/agent/provider.service.ts

@@ -67,7 +67,7 @@ export class ProviderService implements OnModuleInit, OnModuleDestroy {
 
   async onModuleInit(): Promise<void> {
     const authStorage = AuthStorage.inMemory();
-    this.registry = ModelRegistry.inMemory(authStorage);
+    this.registry = new ModelRegistry(authStorage);
 
     // Build the default set of adapters that rely on the registry
     this.adapters = [