chore: move gateway default port from 4000 to 14242

Port 4000 collides with too many dev tools (Phoenix, GraphQL tools, etc.).
Switch to 14242 — unregistered with IANA, no known conflicts, safely within
the User Ports range and outside Linux ephemeral port range (32768+).

Updates all hardcoded defaults across gateway, web client, CLI commands,
playwright config, .env.example, and docs. Bumps @mosaic/cli and
@mosaic/mosaic to 0.0.14.

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

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaic/cli",
-  "version": "0.0.15",
+  "version": "0.0.14",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaic/mosaic-stack.git",

packages/cli/src/commands/gateway/daemon.ts

@@ -211,10 +211,23 @@ const GITEA_REGISTRY = 'https://git.mosaicstack.dev/api/packages/mosaic/npm/';
 
 export function installGatewayPackage(): void {
   console.log('Installing @mosaic/gateway from Gitea registry...');
-  execSync(`npm install -g @mosaic/gateway@latest --@mosaic:registry=${GITEA_REGISTRY}`, {
-    stdio: 'inherit',
-    timeout: 120_000,
-  });
+  // Scope only @mosaic packages to Gitea; all other deps resolve from npmjs normally
+  const npmrcContent = `@mosaic:registry=${GITEA_REGISTRY}\n`;
+  const tmpNpmrc = join(GATEWAY_HOME, '.npmrc');
+  ensureDirs();
+  writeFileSync(tmpNpmrc, npmrcContent);
+  try {
+    execSync(`npm install -g @mosaic/gateway@latest --userconfig=${tmpNpmrc}`, {
+      stdio: 'inherit',
+      timeout: 120_000,
+    });
+  } finally {
+    try {
+      unlinkSync(tmpNpmrc);
+    } catch {
+      // Ignore cleanup failure
+    }
+  }
 }
 
 export function uninstallGatewayPackage(): void {

packages/mosaic/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mosaic/mosaic",
-  "version": "0.0.15",
+  "version": "0.0.14",
   "repository": {
     "type": "git",
     "url": "https://git.mosaicstack.dev/mosaic/mosaic-stack.git",