android: AAssetManager bootstrap + APK asset bundling + scissor TODO

platform/android.sx: `sx_android_bootstrap(app)` now also reads the
ANativeActivity's `assetManager` (offset 64) and `internalDataPath`
(offset 32) into module globals so consumers can route file I/O
through the APK's bundled `assets/` tree.

target.zig (`createApk`): also zips the project's `./assets/`
directory into the APK alongside `lib/<arch>/`. Resolves relative
to the user's CWD at invoke time — matches the convention chess
uses (assets/ next to main.sx).

gles3.sx: scissor is currently a no-op on Android. The renderer's
ScrollView clip_push path feeds bounds that land outside the
framebuffer (clipping everything off-screen). With scissor disabled
the chess board + pieces render correctly. TODO recorded in the
file to fix the bounds path properly.

src/target.zig

@@ -331,6 +331,16 @@ pub fn createApk(allocator: std.mem.Allocator, io: std.Io, so_path: []const u8,
     // and zip is on every macOS/Linux host by default.
     try runProcessIn(allocator, io, stage, &.{ "zip", "-q", "-r", unaligned, "lib/" });
 
+    // Bundle the project's `./assets/` directory (if present) at the APK's
+    // top level so AAssetManager_open(path) at runtime can read them.
+    // Resolves relative to the user's CWD at invocation time — matches the
+    // convention chess uses (assets/ next to main.sx).
+    if (std.Io.Dir.openDir(.cwd(), io, "assets", .{})) |dir_handle| {
+        var dh = dir_handle;
+        dh.close(io);
+        try runProcess(allocator, io, &.{ "zip", "-q", "-r", unaligned, "assets/" });
+    } else |_| {}
+
     // zipalign → aligned apk.
     const aligned = try std.fmt.allocPrint(allocator, "{s}.aligned", .{apk_path});
     try runProcess(allocator, io, &.{ zipalign, "-f", "4", unaligned, aligned });