fix(ci): make artifact uploads non-blocking and fix hardcoded release tokens

- ci.yml: add continue-on-error to APK/AAB upload steps (artifact
  storage not configured on this Gitea instance)
- ci.yml: GITHUB_ENV/GITHUB_PATH fallback for Gitea Actions runners
- release.yml: replace hardcoded '***' tokens with $GITEA_TOKEN env
  var in Create Release and Upload APK/AAB steps

.gitea/workflows/ci.yml

@@ -116,9 +116,10 @@ jobs:
           export PATH="${ANDROID_HOME}/cmdline-tools/latest/bin:${PATH}"
           yes | sdkmanager --licenses >/dev/null 2>&1 || true
           sdkmanager "platform-tools" "platforms;android-35" "build-tools;35.0.0"
-          echo "ANDROID_HOME=${ANDROID_HOME}" >> "${GITHUB_ENV}"
-          echo "${ANDROID_HOME}/cmdline-tools/latest/bin" >> "${GITHUB_PATH}"
-          echo "${ANDROID_HOME}/platform-tools" >> "${GITHUB_PATH}"
+          # Gitea Actions: set env vars for subsequent steps in same job
+          echo "ANDROID_HOME=${ANDROID_HOME}" >> "$GITHUB_ENV" || echo "ANDROID_HOME=${ANDROID_HOME}" >> "$HOME/.env"
+          echo "${ANDROID_HOME}/cmdline-tools/latest/bin" >> "$GITHUB_PATH" || export PATH="${ANDROID_HOME}/cmdline-tools/latest/bin:${PATH}"
+          echo "${ANDROID_HOME}/platform-tools" >> "$GITHUB_PATH" || export PATH="${ANDROID_HOME}/platform-tools:${PATH}"
 
       - name: Pre-cache Android platform artifacts
         run: flutter precache --android
@@ -188,6 +189,7 @@ jobs:
           ls -lh build/app/outputs/bundle/release/ || true
 
       - name: Upload APK artifact
+        continue-on-error: true
         uses: actions/upload-artifact@v4
         with:
           name: android-apk
@@ -195,6 +197,7 @@ jobs:
           retention-days: 90
 
       - name: Upload AAB artifact
+        continue-on-error: true
         uses: actions/upload-artifact@v4
         with:
           name: android-aab