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/modules/compiler.sx

@@ -1,4 +1,4 @@
-OperatingSystem :: enum { macos; linux; windows; wasm; unknown; }
+OperatingSystem :: enum { macos; linux; windows; wasm; ios; unknown; }
 Architecture :: enum { aarch64; x86_64; wasm32; wasm64; unknown; }
 
 OS : OperatingSystem = .unknown;
@@ -7,6 +7,7 @@ POINTER_SIZE : s64 = 8;
 
 BuildOptions :: struct {
     add_link_flag :: (self: BuildOptions, flag: [:0]u8) #compiler;
+    add_framework :: (self: BuildOptions, name: [:0]u8) #compiler;
     set_output_path :: (self: BuildOptions, path: [:0]u8) #compiler;
     set_wasm_shell :: (self: BuildOptions, path: [:0]u8) #compiler;
 }