Add iOS build target for fluxa_core

Phase 0 of the fluxa-android KMP/CMP migration needs an xcframework +
Swift UniFFI bindings for fluxa_core. Adds an "ios" feature (full-api +
uniffi-bindings, no jni/dolby_vision, mirroring the existing "desktop"
feature), a staticlib crate-type for xcframework embedding, a
[bindings.swift] uniffi.toml section, and a macOS-only build script
that produces FluxaCore.xcframework for aarch64-apple-ios and
aarch64-apple-ios-sim.

Verified on Linux: `cargo check --target aarch64-apple-ios --features
ios` and the aarch64-apple-ios-sim equivalent both compile cleanly, so
the crate itself has no Android/JNI-only code leaking into the iOS
feature set. Actual linking/xcframework packaging needs a Mac with
Xcode — untested here.

Cargo.toml

@@ -32,7 +32,7 @@ version = "0.1.0"
 edition = "2021"
 
 [lib]
-crate-type = ["cdylib", "rlib"]
+crate-type = ["cdylib", "staticlib", "rlib"]
 
 [lints]
 workspace = true
@@ -51,6 +51,7 @@ native = [
     "uniffi-bindings",
 ]
 desktop = ["full-api"]
+ios = ["full-api", "uniffi-bindings"]
 full-api = []
 streaming-shared = []
 uniffi-bindings = ["dep:uniffi", "full-api"]

scripts/build-ios-xcframework.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+if [[ "$(uname)" != "Darwin" ]]; then
+    echo "error: this script requires macOS with Xcode command line tools installed" >&2
+    exit 1
+fi
+
+if ! command -v xcodebuild >/dev/null 2>&1; then
+    echo "error: xcodebuild not found — install Xcode" >&2
+    exit 1
+fi
+
+cd "$(dirname "$0")/.."
+
+TARGETS=(aarch64-apple-ios aarch64-apple-ios-sim)
+
+for target in "${TARGETS[@]}"; do
+    rustup target add "$target"
+done
+
+for target in "${TARGETS[@]}"; do
+    cargo build --release --target "$target" --no-default-features --features ios --lib
+done
+
+BINDINGS_DIR="target/uniffi-swift"
+rm -rf "$BINDINGS_DIR"
+mkdir -p "$BINDINGS_DIR"
+
+cargo run --features uniffi-cli --bin uniffi-bindgen generate \
+    --library "target/aarch64-apple-ios/release/libfluxa_core.a" \
+    --language swift \
+    --config uniffi.toml \
+    --out-dir "$BINDINGS_DIR"
+
+HEADERS_DIR="$BINDINGS_DIR/Headers"
+mkdir -p "$HEADERS_DIR"
+mv "$BINDINGS_DIR"/*.h "$HEADERS_DIR"/
+mv "$BINDINGS_DIR"/*.modulemap "$HEADERS_DIR/module.modulemap"
+
+XCFRAMEWORK_OUT="build/ios/FluxaCore.xcframework"
+rm -rf "build/ios"
+mkdir -p "build/ios"
+
+xcodebuild -create-xcframework \
+    -library "target/aarch64-apple-ios/release/libfluxa_core.a" -headers "$HEADERS_DIR" \
+    -library "target/aarch64-apple-ios-sim/release/libfluxa_core.a" -headers "$HEADERS_DIR" \
+    -output "$XCFRAMEWORK_OUT"
+
+echo "xcframework: $XCFRAMEWORK_OUT"
+echo "Swift bindings: $BINDINGS_DIR"/*.swift

uniffi.toml

@@ -3,3 +3,7 @@ package_name = "com.fluxa.core.uniffi"
 android = true
 cdylib_name = "fluxa_core"
 kotlin_target_version = "2.3.0"
+
+[bindings.swift]
+module_name = "FluxaCore"
+cdylib_name = "fluxa_core"