Road-return HUD and inbound AI braking QA (v0.5.61)

Source development only. Neither Unreal Engine 5.8 Editor/UHT, a cookable binary circuit map, installed Windows/Android packages nor real Chaos physics and mobile HUD tests were performed by portable CI.

Off-track detection and nearest paved road

The HUD now runs OffTrackIndicator alongside the existing wrong-way warning. Its route geometry is shared with Source/Latebrake/Public/Track/CircuitLayout.h:

• Horizontal paved roads: X within ±4000 cm, Y within ±800 cm of the north/south road centerlines.
• Vertical paved roads: Y within ±2600 cm, X within ±800 cm of the east/west road centerlines.
• AdviseReturnToCircuit clamps a position against these four paved rectangles, picks the nearest resulting point, and reports direct displacement in meters plus a normalized world-space direction. This is not pathfinding, a guaranteed collision-free return route, or a replacement for the player's paid RECOVER function.
• OffTrackIndicator requires at least 0.8 seconds of continuous off-pavement samples. It resets immediately on pavement, invalid position, menu/pause/focus loss, wrong pawn, new session or teleport. A hitch larger than 0.25 seconds cannot fabricate elapsed alert time.
• The HUD renders OFF TRACK | NEAREST PAVED ROAD ... (expanded) or OFF TRACK | ROAD ... (compact). Warnings do not call checkpoint, racing results, medal, credits or save APIs.

Tests: Tests/Standalone/OffTrackAdvisorTests.cpp, with real IsOnPavedSurface geometry, all four shoulders, diagonal/outside positions, numerical boundaries, NaN/±Infinity/overflow, resets and 100,000 tick saturation. The integration test binds the actual HUD and source CMake target.

Rival corner braking corrected

v0.5.60's speed-based corner anticipation originally used radial distance alone. A car past the target gate or at an incorrect lateral position could be within the radial window and trigger early braking. The corrected AnticipateRivalCorner now:

1. Requires the rival position to be on the actual paved rectangles.
2. Projects corner - position onto the previous-gate→corner segment.
3. Restricts the inbound remaining distance to 440–2200 cm.
4. Restricts cross-track deviation to 620 cm.
5. Preserves the primary pilot's existing steering, stop, collision, motor and verified recovery accounting decisions.

The target speed now depends on the inbound projection instead of radial proximity. New tests cover all four corners, aligned approach, lateral misalignment, driving beyond the gate and off-road cases.

Verification

cmake -S Tests/Standalone -B Tests/Standalone/build -DCMAKE_BUILD_TYPE=Release
cmake --build Tests/Standalone/build --config Release
ctest --test-dir Tests/Standalone/build -C Release -R '^(OffTrackAdvisor|RivalCornerAnticipation|WrongWayIndicator)$' --output-on-failure
python3 -m unittest discover -s Tests/Editor -p '*Tests.py' -v

These checks run only portable C++20 and static Unreal-source integration contracts, not actual Unreal movement or compiled HUD.

Installed game acceptance gates

1. On authorized UE 5.8, compile game/editor targets and use a serialized, cooked, original four-road circuit map. Check source/engine/map hashes.
2. Drive on pavement, all four shoulders and each corner. Confirm no warnings on pavement, delayed off-track detection and immediate reset after returning to the road. Inspect exact nearest-road direction.
3. Recover/RESTART/PAUSE or background the app while off-road; verify the HUD warning clears without changing lap/score/race penalties.
4. On Android compact view, inspect warning clipping/occlusion against steering, GAS/BRAKE, navigation and wrong-way hints at multiple sizes.
5. Play against the rival and record steering/brake/speed traces near each corner, including a post-gate overshoot and track escape. Verify no false automatic lap, paid teleport or finish.
6. Capture reproducible Windows/Android build and gameplay evidence in Android qualification issue #13.

No playable or stable release should be claimed until these gates pass.