ios + ir cleanup

- ios: --target ios/ios-sim shorthands, iOS SDK auto-discovery,
  #framework directive + BuildOptions.add_framework hook,
  .app bundle + Info.plist + codesign (ad-hoc and real),
  --codesign-identity/--provisioning-profile/--entitlements flags,
  modules/std/{objc,uikit}.sx, dynamic class registration,
  typed objc_msgSend cast pattern, UIApplicationMain handoff,
  UIWindow scene attach. Runs on iPhone hardware.
- ir: silent .s64 defaults → loud diagnostics,
  resolveReturnType infers from body, sub-byte int sizes match LLVM,
  tuple type interning includes names, compile errors exit 1
- issue-NNNN convention: resolved bugs rename to focused features
- 50 regression tests passing

examples/60-frameworks.sx

@@ -0,0 +1,12 @@
+// `#framework "Name"` top-level directive registers an Apple framework for
+// linking; `#foreign` declarations can omit the library identifier (frameworks
+// resolve symbols by global namespace at link time).
+
+#framework "CoreFoundation";
+
+CFAbsoluteTimeGetCurrent :: () -> f64 #foreign;
+
+main :: () -> s32 {
+    t := CFAbsoluteTimeGetCurrent();
+    return if t > 0.0 then 0 else 1;
+}