ffi 1.29: retire the C sx_android_query_safe_insets body

Closes the Phase 1D migration for the safe-insets JNI chain. The C
function and its `#foreign` declaration in `android.sx` are gone;
all dispatch now goes through the sx-side `#jni_call` machinery
plus the JavaVM helpers landed in 1.26.

What's gone from `library/vendors/sx_android_jni/sx_android_jni.c`:
- `#include <android/native_activity.h>` and `<jni.h>` (no longer
  needed without the JNI body).
- `sx_android_query_safe_insets` — 55 lines of `(*env)->Foo` chain
  with manual `goto done` early-exit. Migrated to
  `library/modules/platform/android.sx::sx_query_safe_insets_jni`
  in 1.25 (15 lines of `#jni_call`).

What stays:
- `sx_android_install_input_handler` — non-JNI; struct-field
  assignment against `struct android_app`'s `onInputEvent` slot.
  No sx equivalent yet (would need to either land a `#android_app`-
  style intrinsic or hand-roll the offset, neither of which is
  Phase 1 scope).
- `<android/input.h>` and the `struct sx_android_app_min` mirror
  needed by the input-handler installer.

Net diff: -55 lines in the .c file, -1 line `#foreign` decl in
android.sx. Phase 2 (declarative JNI imports) will revisit whether
the .c file can be deleted entirely (the input-handler hop may
move into a different shape).

Verification:
- zig build + zig test + run_examples + cross_compile all green.
  Notable: the previously-failing `ffi-objc-call-12-rect-u64-returns`
  also passes now — looks like the working-tree `#import c` work
  was tidied up alongside.
- chess Android APK rebuilt + reinstalled + launched on Pixel
  device; safe-insets behavior unchanged (board top edge sits below
  the status bar correctly, all pieces in starting positions, no
  status-bar overlap).

library/modules/platform/android.sx

@@ -51,8 +51,11 @@ AMotionEvent_getAction      :: (event: *void) -> s32 #foreign;
 AMotionEvent_getX           :: (event: *void, pointer_index: u64) -> f32 #foreign;
 AMotionEvent_getY           :: (event: *void, pointer_index: u64) -> f32 #foreign;
 
-// JNI/glue bridges from vendors/sx_android_jni/sx_android_jni.c.
-sx_android_query_safe_insets        :: (activity: *void, top: *s32, left: *s32, bottom: *s32, right: *s32) -> void #foreign;
+// Glue bridge from vendors/sx_android_jni/sx_android_jni.c. The
+// safe-insets JNI chain that used to live in that file was migrated
+// to sx (see `sx_query_safe_insets_jni` below) — what remains is the
+// input-handler installer, which is plain struct-field plumbing
+// rather than JNI dispatch.
 sx_android_install_input_handler    :: (app: *void, handler: (*void, *void) -> s32) -> void #foreign;
 
 // JavaVM vtable indirection — used to attach the calling thread to

library/vendors/sx_android_jni/sx_android_jni.c

@@ -2,11 +2,16 @@
 // so consumers don't need to vendor an identically-named copy. The sx
 // compiler resolves `#source "vendors/..."` against the stdlib search
 // paths in addition to the consumer's project root.
+//
+// The safe-insets JNI chain that used to live here was migrated to
+// sx in Phase 1D of the FFI plan (see `library/modules/platform/
+// android.sx::sx_query_safe_insets_jni` and the JavaVM helpers
+// alongside it). What remains is the input-handler installer, which
+// is a plain C struct-field assignment rather than JNI dispatch and
+// has no sx equivalent yet.
 
 #ifdef __ANDROID__
-#include <android/native_activity.h>
 #include <android/input.h>
-#include <jni.h>
 
 // Mirror of struct android_app (NDK 29 / arm64) up to the fields we touch.
 // Avoids depending on the glue header in the sx library compile path.
@@ -26,69 +31,4 @@ void sx_android_install_input_handler(void* app,
     struct sx_android_app_min* a = (struct sx_android_app_min*)app;
     a->onInputEvent = (int (*)(struct sx_android_app_min*, AInputEvent*))handler;
 }
-
-// Query system-bar insets (status bar, nav bar) via JNI:
-//   activity → getWindow() → getDecorView()
-//            → getRootWindowInsets()
-//            → getSystemWindowInset[Top|Left|Bottom|Right]()
-// Out params receive physical-pixel insets; the sx caller divides by
-// dpi_scale to convert to logical units. Falls back to zeros if the
-// view isn't attached yet (e.g. called before the first frame).
-void sx_android_query_safe_insets(void* activity_ptr,
-                                  int* out_top, int* out_left,
-                                  int* out_bottom, int* out_right) {
-    *out_top = 0; *out_left = 0; *out_bottom = 0; *out_right = 0;
-    if (activity_ptr == 0) return;
-
-    ANativeActivity* act = (ANativeActivity*)activity_ptr;
-    JavaVM* vm = act->vm;
-    if (vm == 0) return;
-
-    JNIEnv* env = 0;
-    int already_attached = 1;
-    if ((*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_6) != JNI_OK) {
-        already_attached = 0;
-        if ((*vm)->AttachCurrentThread(vm, &env, 0) != 0) return;
-    }
-
-    jobject activity_obj = act->clazz;
-    jclass activity_cls = (*env)->GetObjectClass(env, activity_obj);
-
-    jmethodID m_getWindow = (*env)->GetMethodID(env, activity_cls,
-        "getWindow", "()Landroid/view/Window;");
-    if (m_getWindow == 0) goto done;
-    jobject window = (*env)->CallObjectMethod(env, activity_obj, m_getWindow);
-    if (window == 0) goto done;
-
-    jclass window_cls = (*env)->GetObjectClass(env, window);
-    jmethodID m_getDecorView = (*env)->GetMethodID(env, window_cls,
-        "getDecorView", "()Landroid/view/View;");
-    if (m_getDecorView == 0) goto done;
-    jobject decor = (*env)->CallObjectMethod(env, window, m_getDecorView);
-    if (decor == 0) goto done;
-
-    jclass view_cls = (*env)->GetObjectClass(env, decor);
-    jmethodID m_getRootInsets = (*env)->GetMethodID(env, view_cls,
-        "getRootWindowInsets", "()Landroid/view/WindowInsets;");
-    if (m_getRootInsets == 0) goto done;
-    jobject insets = (*env)->CallObjectMethod(env, decor, m_getRootInsets);
-    if (insets == 0) goto done;
-
-    jclass insets_cls = (*env)->GetObjectClass(env, insets);
-    jmethodID m_top = (*env)->GetMethodID(env, insets_cls,
-        "getSystemWindowInsetTop", "()I");
-    jmethodID m_left = (*env)->GetMethodID(env, insets_cls,
-        "getSystemWindowInsetLeft", "()I");
-    jmethodID m_bottom = (*env)->GetMethodID(env, insets_cls,
-        "getSystemWindowInsetBottom", "()I");
-    jmethodID m_right = (*env)->GetMethodID(env, insets_cls,
-        "getSystemWindowInsetRight", "()I");
-    if (m_top)    *out_top    = (*env)->CallIntMethod(env, insets, m_top);
-    if (m_left)   *out_left   = (*env)->CallIntMethod(env, insets, m_left);
-    if (m_bottom) *out_bottom = (*env)->CallIntMethod(env, insets, m_bottom);
-    if (m_right)  *out_right  = (*env)->CallIntMethod(env, insets, m_right);
-
-done:
-    if (!already_attached) (*vm)->DetachCurrentThread(vm);
-}
 #endif