GiteaPR: native iOS app to manage Gitea pull requests

Multi-repo PR inbox, review (approve/request changes/comment), merge with
gating toggle, read-only diff viewer, and Gitea Actions check status with
one-tap re-run. Ships unsigned via the iMac runner to the SideStore source.

GiteaPR/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}