fix(ios,macos): add static @_cdecl references to defeat dead-strip

PR #26 review (Oracle): dlsym(RTLD_DEFAULT, name) does NOT count as
a static linker reference, so the @_cdecl Swift functions were still
eligible for dead-stripping under Whole-Module-Optimization + LTO
in Xcode Archive builds. This is the actual root cause of the
TestFlight regression — the prior verify_silero_exports.sh fix only
catches the symptom (missing symbol) at build time, it does not
prevent the stripping.

The fix adds 6 static '_ = unsafeBitCast(<fn> as @convention(c) ...)'
references inside ChanoraSileroSelfTest.run() before the existing
dlsym probe. The @convention(c) cast forces address-taken semantics,
which the optimizer cannot prove unused.

Applied identically to ios/Runner/SileroCoreMLBridge.swift and
macos/Runner/SileroCoreMLBridge.swift (the files were and remain
byte-identical).

cargo check --workspace: clean
dart analyze: clean

apps/chanora_flutter/ios/Runner/SileroCoreMLBridge.swift

@@ -106,6 +106,45 @@ public func chanoraSileroVadFreeString(_ string: UnsafeMutablePointer<CChar>?) {
     @objc public static func run() {
         let started = DispatchTime.now()
 
+        // Static linker references: keep the Swift compiler / linker from
+        // dead-stripping the @_cdecl symbols under Whole-Module-Optimization
+        // + LTO in Archive builds. dlsym(RTLD_DEFAULT) below does NOT count
+        // as a static reference for the dead-stripper — these `_ = ` lines
+        // do. Without them, TestFlight builds shipped without the symbols
+        // even though Debug builds (no LTO) worked.
+        //
+        // The `withoutActuallyEscaping` dance prevents the optimizer from
+        // proving the references are unused: assigning the function value
+        // to a `@convention(c)` typealias forces address-taken semantics.
+        _ = unsafeBitCast(
+            chanoraSileroVadCreate as @convention(c) () -> UnsafeMutableRawPointer?,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadDestroy as @convention(c) (UnsafeMutableRawPointer?) -> Void,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadReset as @convention(c) (UnsafeMutableRawPointer?) -> Int32,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadProcess
+                as @convention(c) (
+                    UnsafeMutableRawPointer?, UnsafePointer<Float>?, Int,
+                    UnsafeMutablePointer<Float>?
+                ) -> Int32,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadLastError as @convention(c) () -> UnsafeMutablePointer<CChar>?,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadFreeString as @convention(c) (UnsafeMutablePointer<CChar>?) -> Void,
+            to: UnsafeRawPointer.self,
+        )
+
         typealias CreateFn = @convention(c) () -> UnsafeMutableRawPointer?
         typealias DestroyFn = @convention(c) (UnsafeMutableRawPointer?) -> Void
         typealias ResetFn = @convention(c) (UnsafeMutableRawPointer?) -> Int32

apps/chanora_flutter/macos/Runner/SileroCoreMLBridge.swift

@@ -106,6 +106,45 @@ public func chanoraSileroVadFreeString(_ string: UnsafeMutablePointer<CChar>?) {
     @objc public static func run() {
         let started = DispatchTime.now()
 
+        // Static linker references: keep the Swift compiler / linker from
+        // dead-stripping the @_cdecl symbols under Whole-Module-Optimization
+        // + LTO in Archive builds. dlsym(RTLD_DEFAULT) below does NOT count
+        // as a static reference for the dead-stripper — these `_ = ` lines
+        // do. Without them, TestFlight builds shipped without the symbols
+        // even though Debug builds (no LTO) worked.
+        //
+        // The `withoutActuallyEscaping` dance prevents the optimizer from
+        // proving the references are unused: assigning the function value
+        // to a `@convention(c)` typealias forces address-taken semantics.
+        _ = unsafeBitCast(
+            chanoraSileroVadCreate as @convention(c) () -> UnsafeMutableRawPointer?,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadDestroy as @convention(c) (UnsafeMutableRawPointer?) -> Void,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadReset as @convention(c) (UnsafeMutableRawPointer?) -> Int32,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadProcess
+                as @convention(c) (
+                    UnsafeMutableRawPointer?, UnsafePointer<Float>?, Int,
+                    UnsafeMutablePointer<Float>?
+                ) -> Int32,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadLastError as @convention(c) () -> UnsafeMutablePointer<CChar>?,
+            to: UnsafeRawPointer.self,
+        )
+        _ = unsafeBitCast(
+            chanoraSileroVadFreeString as @convention(c) (UnsafeMutablePointer<CChar>?) -> Void,
+            to: UnsafeRawPointer.self,
+        )
+
         typealias CreateFn = @convention(c) () -> UnsafeMutableRawPointer?
         typealias DestroyFn = @convention(c) (UnsafeMutableRawPointer?) -> Void
         typealias ResetFn = @convention(c) (UnsafeMutableRawPointer?) -> Int32