fix(android): use --wrap=pthread_create instead of raw symbol override

Build #10 failed with:
  ld.lld: error: duplicate symbol: pthread_create
    >>> defined at pthread_shim.c:30
    >>> ... in archive libpthread_shim.a
  (the other definition coming from libstd's bundled libc.a stub)

The raw-symbol-override approach was naive: when two static archives
both define the same symbol the linker refuses instead of picking one.

Switch to GNU-ld's `--wrap=pthread_create` mechanism:
  - All `pthread_create` references get rewritten to `__wrap_pthread_create`
  - Our shim now defines `__wrap_pthread_create` (no symbol clash)
  - Inside the shim we `dlopen("libc.so")` + `dlsym("pthread_create")` to
    get the real runtime symbol directly, bypassing BOTH the broken static
    stub (libstd's libc.a copy) AND libstd's own pthread_create path
  - `--real_pthread_create` is deliberately NOT used — it would alias the
    same broken stub the wrap exists to avoid

The wrap flag is emitted via `cargo:rustc-link-arg` in build.rs so it
only affects the Android target (the Android-branch of build.rs is the
only place that emits it).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

desktop/src-tauri/build.rs

@@ -112,6 +112,12 @@ fn build_oboe_android(target: &str) {
     // Oboe requires Android log + OpenSLES backends
     println!("cargo:rustc-link-lib=log");
     println!("cargo:rustc-link-lib=OpenSLES");
+
+    // Wrap pthread_create: redirect every `pthread_create` reference to our
+    // `__wrap_pthread_create` in pthread_shim.c, which forwards to the real
+    // libc.so symbol via dlsym. Without this the linker binds to libstd's
+    // bundled broken static pthread_create stub (see pthread_shim.c).
+    println!("cargo:rustc-link-arg=-Wl,--wrap=pthread_create");
 }
 
 /// Recursively add all .cpp files from a directory to a cc::Build.