feat(ios,p0): iOS P0 platform, audio fixes, channel UX

.cargo/config.toml

@@ -0,0 +1,40 @@
+# Environment variables set for all cargo invocations in this workspace.
+# CMAKE_POLICY_VERSION_MINIMUM is required for audiopus_sys's bundled
+# Opus CMake build to succeed on CMake 4.x (which removed compatibility
+# with cmake_minimum_required < 3.5). audiopus_sys v0.2.2 bundles
+# Opus 1.3.1 whose CMakeLists.txt uses a very old minimum version.
+#
+# IPHONEOS_DEPLOYMENT_TARGET=13.0 is required for iOS builds because
+# ___chkstk_darwin (the stack-probe symbol emitted by clang for functions
+# with large stack frames) only exists in the iOS 13.0+ runtime.  The
+# pre-built libopus.a and any C code compiled by the cc crate reference
+# this symbol.  Without this env var, the cc crate compiles C code
+# targeting iOS 10.0 (the Rust default), producing object files that
+# reference ___chkstk_darwin but can't resolve it against the 10.0
+# runtime.  Setting IPHONEOS_DEPLOYMENT_TARGET=13.0 ensures the cc crate
+# and CMake both target iOS 13.0+, where ___chkstk_darwin exists.
+# (DEC-003: minimum deployment target iOS 13.0)
+[env]
+CMAKE_POLICY_VERSION_MINIMUM = "3.5"
+IPHONEOS_DEPLOYMENT_TARGET = "13.0"
+
+# iOS target linker flags (DEC-003: minimum deployment target iOS 13.0).
+#
+# These rustflags pass -miphoneos-version-min=13.0 to the linker, ensuring
+# the final binary targets iOS 13.0+.  This is defense-in-depth alongside
+# the IPHONEOS_DEPLOYMENT_TARGET env var above — the env var affects C
+# compilation (cc crate, CMake), while these rustflags affect the final
+# link step.
+#
+# NOTE: The canonical iOS build is done via tools/build-ios.sh, which
+# sets LIBOPUS_STATIC=1, LIBOPUS_NO_PKG=1, and LIBOPUS_LIB_DIR to
+# bypass audiopus_sys's CMake build entirely.
+
+[target.aarch64-apple-ios]
+rustflags = ["-C", "link-arg=-miphoneos-version-min=13.0"]
+
+[target.aarch64-apple-ios-sim]
+rustflags = ["-C", "link-arg=-miphonesimulator-version-min=13.0"]
+
+[target.x86_64-apple-ios]
+rustflags = ["-C", "link-arg=-miphonesimulator-version-min=13.0"]