Add E2E-tested examples, fix CGo pointer bugs, add GitHub CI

Examples:
- Add 12 new examples covering audio, camera, EGL, GLES, input, media,
  NNAPI, sensor, thermal, trace, hardware buffer, surface texture, window
- All 59 examples verified passing on Android emulator (E2E)
- Remove 7 non-runnable examples (font, vulkan, net, media/extractor-info)

Code generator fixes:
- Fix capigen return value conversion for opaque pointer types: use direct
  cast instead of incorrect double-dereference that caused SIGSEGV
- Fix capigen ** parameter handling: pin both outer and inner pointers
  with runtime.Pinner to satisfy CGo's pointer check (fixes gles2/gles3)
- Fix nnapi/model_add_operand.go: pin struct with Go pointer fields

CI/Testing:
- Add .github/workflows/ci.yml with unit tests, golangci-lint, example
  cross-compilation, and manual-trigger emulator E2E job
- Add .golangci.yml configuration
- Add e2e/run-examples.sh and Makefile e2e-examples target
- Add examples/build_test.go for Go test-based cross-compilation check
- Fix 14 golangci-lint warnings across tools packages

Author: xaionaro@dx.center

.github/workflows/ci.yml

@@ -0,0 +1,112 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+env:
+  ANDROID_NDK_VERSION: r27c
+  ANDROID_NDK_DIR_NAME: "27.2.12479018"
+
+jobs:
+  test:
+    name: Unit Tests & Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+
+      - name: Run unit tests
+        run: make test
+
+      - name: Lint
+        uses: golangci/golangci-lint-action@v9
+        with:
+          version: latest
+          args: --timeout=5m ./tools/...
+
+  check-examples:
+    name: Cross-compile Examples
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+
+      - name: Install Android NDK
+        run: |
+          mkdir -p "$HOME/Android/Sdk/ndk"
+          wget -q "https://dl.google.com/android/repository/android-ndk-${ANDROID_NDK_VERSION}-linux.zip" -O /tmp/ndk.zip
+          unzip -q /tmp/ndk.zip -d "$HOME/Android/Sdk/ndk/"
+          mv "$HOME/Android/Sdk/ndk/android-ndk-${ANDROID_NDK_VERSION}" "$HOME/Android/Sdk/ndk/${ANDROID_NDK_DIR_NAME}"
+
+      - name: Cross-compile examples for Android arm64
+        run: make check-examples
+
+  e2e-examples:
+    name: E2E Examples (Emulator)
+    runs-on: ubuntu-latest
+    if: github.event_name == 'workflow_dispatch'
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+
+      - name: Enable KVM
+        run: |
+          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
+          sudo udevadm control --reload-rules
+          sudo udevadm trigger --name-match=kvm
+
+      - name: Install Android SDK components
+        uses: android-actions/setup-android@v3
+        with:
+          packages: |
+            platform-tools
+            emulator
+            system-images;android-35;google_apis;x86_64
+            platforms;android-35
+
+      - name: Install Android NDK
+        run: |
+          mkdir -p "$ANDROID_HOME/ndk"
+          wget -q "https://dl.google.com/android/repository/android-ndk-${ANDROID_NDK_VERSION}-linux.zip" -O /tmp/ndk.zip
+          unzip -q /tmp/ndk.zip -d "$ANDROID_HOME/ndk/"
+          mv "$ANDROID_HOME/ndk/android-ndk-${ANDROID_NDK_VERSION}" "$ANDROID_HOME/ndk/${ANDROID_NDK_DIR_NAME}"
+
+      - name: Create AVD
+        run: |
+          echo "no" | avdmanager create avd \
+            -n e2e_examples -k "system-images;android-35;google_apis;x86_64" --force
+
+      - name: Start emulator
+        run: |
+          $ANDROID_HOME/emulator/emulator \
+            -avd e2e_examples -no-window -no-audio -no-boot-anim \
+            -gpu swiftshader_indirect -no-metrics &
+          echo "Waiting for emulator boot..."
+          adb wait-for-device
+          for i in $(seq 1 60); do
+            RESULT=$(adb shell getprop sys.boot_completed 2>/dev/null | tr -d '\r\n')
+            if [ "$RESULT" = "1" ]; then
+              echo "Emulator booted after ~$((i*5))s"
+              break
+            fi
+            sleep 5
+          done
+
+      - name: Run examples E2E
+        run: make e2e-examples

.gitignore

@@ -7,15 +7,18 @@ e2e/e2e_test
 _build/
 capi/manifests/.gen_*.yaml
 
-# Built binaries (go build outputs)
+# Built binaries (go build outputs in repo root)
 /basic-loop
 /capigen
+/capture-session
 /check-permissions
+/event-loop
 /headerspec
 /idiomgen
 /manager
 /null
 /obb-manager
+/offscreen-render
 /overview
 /specgen
 /sync-fences

.golangci.yml

@@ -0,0 +1,20 @@
+version: "2"
+
+run:
+  timeout: 5m
+
+linters:
+  enable:
+    - errcheck
+    - govet
+    - ineffassign
+    - staticcheck
+    - unused
+
+formatters:
+  enable:
+    - gofmt
+
+issues:
+  max-issues-per-linter: 0
+  max-same-issues: 0

Makefile

@@ -17,7 +17,7 @@ FIXTURE_MODULES := $(notdir $(wildcard tools/pkg/specgen/testdata/*/))
 NDK_SYSROOT := $(NDK_PATH)/toolchains/llvm/prebuilt/linux-x86_64/sysroot/usr/include
 C2FFI_BIN   ?= c2ffi
 
-.PHONY: all capi specs idiomatic clean regen fixtures test e2e e2e-build
+.PHONY: all capi specs idiomatic clean regen fixtures test lint check-examples e2e e2e-build e2e-examples
 
 all: specs capi idiomatic
 
@@ -85,6 +85,15 @@ regen: clean specs capi idiomatic
 test:
 	go test $$(go list ./... | grep -v -E '/(capi|e2e|examples)/|/ndk/[a-z][a-z0-9]*$$') -count=1
 
+lint:
+	golangci-lint run ./tools/...
+
+# Cross-compile all examples for Android arm64 to catch compile errors (requires NDK)
+check-examples:
+	CGO_ENABLED=1 GOOS=android GOARCH=arm64 \
+		CC=$(NDK_PATH)/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android35-clang \
+		go build ./examples/...
+
 # Cross-compile E2E test binary for Android x86_64 (requires NDK)
 e2e-build:
 	CGO_ENABLED=1 GOOS=android GOARCH=amd64 \
@@ -95,6 +104,10 @@ e2e-build:
 e2e: e2e-build
 	ANDROID_HOME=$(dir $(NDK_PATH)) ./e2e/run.sh
 
+# Run all examples on Android emulator (requires running emulator + NDK)
+e2e-examples:
+	./e2e/run-examples.sh
+
 clean:
 	@for m in $(MODULES); do rm -rf "capi/$$m/"; done
 	rm -rf spec/generated/