android: build the x86_64 ABI too, so an emulator can run it (task 1864)

arm64 is every real device, but a desktop emulator is x86_64 — an arm64-only APK
installs there and then dies unable to load its native library. A build nobody
can try on an emulator is a build nobody checks, which defeats the point of
producing an artifact at all while there is no phone in the loop.

armv7 and i686 stay out: 32-bit hardware we do not target, and the image carries
all four targets if that ever changes.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.forgejo/workflows/android.yml

@@ -59,9 +59,11 @@ jobs:
       # anyone, so this lane can prove the app COMPILES and PACKAGES today and grow
       # a signed release job when a keystore exists.
       #
-      # arm64 only because it is every real device; adding the armv7 and two x86
-      # emulator ABIs quadruples the build for coverage nothing currently checks.
-      # The image carries all four targets, so widening this is a one-word change.
+      # arm64 + x86_64. arm64 is every real device; x86_64 is what a desktop
+      # emulator runs, and an arm64-only APK installs there and then dies unable to
+      # load its native library — so a build nobody can try on an emulator is a
+      # build nobody checks. armv7 and i686 are left out: 32-bit hardware we do not
+      # target, and the image carries all four if that changes.
       - name: Tauri build (Android APK)
         run: |
           version="$(sh ../packaging/build-version.sh)"
@@ -69,6 +71,7 @@ jobs:
           cargo tauri android build \
             --debug \
             --target aarch64 \
+            --target x86_64 \
             --config '{"build":{"beforeBuildCommand":""}}' \
             --config "{\"version\":\"$version\"}"
         working-directory: desktop/src-tauri