Differentiate manual vs auto-injected `sentry-label` for masking

[antonis]

Problem Statement

When Session Replay masking is active (maskAllText: true, the default), the SDK skips all sentry-label props to prevent leaking masked text content into breadcrumbs. However, this also silently ignores manually set sentry-label props that developers use for component tracking — these are developer-provided identifiers (like "checkout-button"), not user-visible text, and should not be affected by masking.

The SDK cannot distinguish between the two at runtime because both are just sentry-label string props.

Proposed Solution

Use a different prop name for auto-injected labels in the Babel plugin (e.g., data-sentry-label), and update the SDK to handle them separately:

• sentry-label (manual) — always read, never skipped by masking
• data-sentry-label (auto-injected) — skipped when maskAllText is enabled or inside a Sentry.Mask boundary

This requires a coordinated change in:

1. @sentry/babel-plugin-component-annotate — inject as data-sentry-label instead of sentry-label
2. @sentry/react-native — update getLabelValue() in touchevents.tsx to read both props with different masking behavior

Context

Part of the "Making breadcrumbs data more useful" project. The masking behavior was introduced in #6142, and the auto-injection in #6141.

[linear-code]

RN-626

[antonis]

After investigation, we're closing this as won't fix for now.

Why

At runtime, manual and auto-injected sentry-label props are indistinguishable — they both arrive as the same prop on the component. Fixing this would require changes in the upstream Babel plugin (@sentry/babel-plugin-component-annotate) to emit a different prop name (e.g., data-sentry-auto-label) for auto-injected labels, plus corresponding SDK changes to handle both props. This creates cross-package coordination and version coupling for a narrow use case.

Impact

The current behavior — all sentry-label props are skipped when Session Replay's maskAllText is enabled (the default) — is consistent and predictable. Users who need component tracking alongside masking have several alternatives that are never affected by masking:

• accessibilityLabel prop
• aria-label prop
• testID prop
• Custom labelName configured on the TouchEventBoundary

These are documented in the touch events configuration guide.

Reopening criteria

If we see significant user demand for distinguishing manual vs auto-injected sentry-label, we can revisit with a Babel plugin change. Until then, the recommended path is to use accessibilityLabel or testID for tracking when masking is active.