[r3dbars]

What changed

• center each stable subtitle row horizontally
• keep the complete one- or two-line reading block vertically centered
• preserve fixed card geometry and stable whole-row advancement
• add a native XS visual receipt and document the interaction decision

What did not change

• model, audio capture, reducer capacities, row boundaries, tentative suffix behavior, panel position, and privacy boundaries

Verification

• ./scripts/run-tests.sh (45 tests plus privacy smoke)
• ./scripts/build-and-run.sh --verify
• native preview capture: docs/assets/caption-centered-composition.jpeg
• release receipt: Artifacts/Receipts/Release/release-20260823T183350Z.json

[r3dbars]

Closed after live reading feedback: horizontally centered streaming rows move their starting edge as words arrive, which makes captions harder to track. Said keeps the fixed left reading rail and vertical optical centering already on main.