Signing: rebrand bundle IDs to xyz.blakeslee.* and correct the Team ID

Desktop channels → xyz.blakeslee.nucleic.desktop.{dev,beta,rc,release} (the stable channel keyword is unchanged; only its bundle-id suffix is "release"). iOS remote → xyz.blakeslee.nucleic.remote, including its Keychain account namespaces, the scanner log subsystem, and the coupled APNS topic.

Correct the Apple Developer Team ID to L7UDTQ6F5W across the Xcode project, ExportOptions, the APNS config + tests, and the signing/cloud docs.

Co-Authored-By: Claude Opus 4.8 <[email protected]>

ExportOptions.plist

@@ -7,7 +7,7 @@
 
   Note: `method = app-store-connect` is the current name (Xcode 15.3+). On older Xcode use
   `app-store` instead. Signing is automatic — Xcode manages the distribution profile for team
-  3XPAYVD6BP (needs an "Apple Distribution" cert + the App ID registered; see signing/README.md).
+  L7UDTQ6F5W (needs an "Apple Distribution" cert + the App ID registered; see signing/README.md).
 -->
 <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 <plist version="1.0">
@@ -17,7 +17,7 @@
     <key>destination</key>
     <string>upload</string>
     <key>teamID</key>
-    <string>3XPAYVD6BP</string>
+    <string>L7UDTQ6F5W</string>
     <key>signingStyle</key>
     <string>automatic</string>
     <key>uploadSymbols</key>