Hydration Guardian Overview Ensures zero-mismatch integrity between server-rendered HTML and client-side React trees. Covers hydration error diagnosis, selective hydration via Suspense boundaries, deterministic data bridges with the React 19 hook, for eliminating data drift, two-pass rendering for client-only content, React 19's single-diff hydration error reporting for pinpointing exact mismatches, and automated validation of rendered DOM state. When to use: Debugging hydration mismatch errors, fixing text content mismatches, handling browser extension DOM pollution, implementing determinist…