feat(gradle-plugin): default release mode to event

[ablaszkiewicz]

Related PRs

Event mode is live today. Each build must ask for it. These PRs make it the default. The modes themselves do not change.

• feat(cli): default release mode to event posthog#91823
• feat(plugins): default release mode to event posthog-js#4705
• feat(react-native): default release mode to event posthog-js#4706
• feat(gradle-plugin): default release mode to event #739 ← this PR
• feat: upload dsym symbol sets release-independent by default posthog-ios#789

Problem

• Two Android releases that ship the same proguard mapping report their exceptions on one release.
• The release that uploads the mapping first takes them.

Changes

• posthog.releaseMode defaults to event.
• The build uploads the proguard mapping without a release.
• Each event resolves its own release from the $app_namespace, $app_version and $app_build the SDK sends.
• posthog.releaseMode=symbol-set keeps the old behavior. POSTHOG_RELEASE_MODE=symbol-set does the same.
• PostHogUploadProguardMappingsTask.register takes the same default.

How did you test this code?

• ./gradlew :posthog-android-gradle-plugin:test and ./gradlew spotlessCheck detekt.
• PostHogReleaseModeTest is new. resolvePostHogReleaseMode had no tests.
• Not run: the functional tests. This change does not touch them.

🤖 Agent context

Autonomy: Human-driven (agent-assisted)

Written with Claude Code (Opus 5).

The test helper builds its Project without apply {}. Project has its own apply(), so the scope function resolves to Gradle's method.

[posthog]

🦔 PostHog Review reviewed this pull request

Found 1 must fix, 1 should fix, 0 consider.

Published 2 findings (view the review).

[posthog]

PostHog Review alpha 🦔 If you find any issues helpful - please reply "valid", "invalid", etc., for evaluation purposes 🙏

[posthog]

PostHog Review

Found 1 must fix, 1 should fix.

[ablaszkiewicz]

Closing this. We are removing event release mode from this package instead of defaulting to it.

Event mode only helps when two releases ship a byte-identical artifact. The symbol id is a content hash on every platform, so an ordinary feature release already gets its own symbol set and never collides. The case that does collide is a React Native release that changes only JavaScript, where the native artifact repeats.

Against that narrow benefit, the mobile paths carry real cost. A dSYM upload covers every embedded target but creates one release, so an extension crash resolves no release once the binding is gone.

A replacement PR follows that removes the mode from this package. The flag was experimental and undocumented, so the removal is direct.