[waveshare-ugv] Make supervised physical navigation fail closed

[superposition]

Tracks #168; keep the issue open until the supervised Pinkie acceptance artifacts are attached.

Depends on #165, #166, and #167. This PR is stacked on #180.

What changed

• add guarded HTTP goal/status/cancel routes and pass token/approval through saved patrol starts
• retain validated simulator planner/patrol authorization across continuation steps, clearing it on stop, cancel, E-stop, deadman, collision, or failure
• require physical pose covariance at or below 0.15 m X/Y sigma and 10 degrees yaw sigma throughout execution
• pin the active map identity for the physical authorization lease and cancel on replacement
• require a polygon boundary for physical saved patrols, prove every waypoint is inside it/on the same map, advance each waypoint once, and send zero speed at the terminal waypoint
• extend dedicated zero-speed cancellation proofs for token replacement/expiry, approval loss, deadman, distance limit, provider/lidar loss, obstacle, covariance, map replacement, stop, and E-stop
• add a loopback-only Pinkie field runner with explicit floor/spotter/E-stop confirmation, private token input, resource capture, normal Leash replay validation, hashes, and final-stop proof
• link the concrete field workflow from the main README while keeping generic Leash vs Waveshare UGV implementation ownership explicit

Definition of done

• Physical navigation remains behind independent compile/runtime/actuation gates.
• Goal/path and localization providers still have no motor-device ownership; final drive calls remain Leash-owned.
• Token, approval, low-speed cap, lidar/localization freshness, covariance, deadman, obstacle, map identity, and soft-distance checks run at start and continuation.
• Dedicated no-hardware proofs cancel every safety path and produce zero command state.
• Saved physical patrols require a bounded polygon and stop after exactly one pass through the saved waypoint list.
• Failed/cancelled runs clear planner, patrol, and authorization state; restart state is not persisted.
• Every field run is forced to capture supervised-safety assertions, telemetry/resources, replay, hashes, and final zero speed.
• Supervised 0.5 m goal completes within 0.15 m on Pinkie.
• Three consecutive supervised map-frame goals complete with final pose and stop evidence.
• One explicitly bounded Pinkie patrol completes one circuit and stops at its terminal waypoint.
• Full five-run private evidence set passes navigation/verify.py and is linked in scrubbed form.

Verification

• cargo clippy --all-targets --all-features -- -D warnings
• cargo test --all-targets --all-features (179 library + 4 binary tests)
• scripts/smoke-all.sh (28/28 no-hardware checks)
• implementations/waveshare-ugv/navigation/verify.sh
• cargo package --allow-dirty (130 files; package verification passed)

No physical motion was performed in this PR. It stays draft until the SSH identity gate, #165 soak, #166 measured calibration, and on-site acceptance runs are complete.