Add builder service: scaffold, ASC API, devices UI, fastlane profile manager

Phase 1-3 of the builder subsystem on the Mac mini:
- Express + SQLite + sessions scaffolding, LAN-only service on port 3090
- App Store Connect JWT client (ES256 signing, devices/profiles/bundleIds)
- Device management UI with Apple-side registration
- Fastlane sigh wrapper with profile cache + auto-install to ~/Library/
- launchd plist + deploy script for Mac mini supervision

builder/fastlane/Fastfile

@@ -0,0 +1,22 @@
+default_platform(:ios)
+
+platform :ios do
+  desc "Generate or refresh an ad-hoc provisioning profile for the given app identifier."
+  lane :generate_adhoc do |options|
+    app_identifier = options[:app_identifier] || ENV['APP_IDENTIFIER']
+    output_path = options[:output_path] || ENV['OUTPUT_PATH'] || Dir.pwd
+    api_key_path = options[:api_key_path] || ENV['ASC_KEY_JSON']
+
+    UI.user_error!("app_identifier is required") unless app_identifier && !app_identifier.empty?
+    UI.user_error!("api_key_path is required") unless api_key_path && File.exist?(api_key_path)
+
+    sigh(
+      adhoc: true,
+      force: true,
+      app_identifier: app_identifier,
+      api_key_path: api_key_path,
+      output_path: output_path,
+      skip_install: true,
+    )
+  end
+end