Publish lossless applied-action evidence

[superposition]

What changed

• publish boot-scoped, contiguous post-safety wheel-command intervals from Leash
• expose paginated read-only evidence at /evidence/action/applied and /action-evidence
• record requested, clamped, and adapter-accepted values with safety provenance
• fail explicitly on bounded-history overrun and document the consumer contract

Why

Qualia's JEPA recorder needs authoritative applied-action supervision. Reconstructing action from UI requests or sampled telemetry can silently miss clamps, deadman stops, and intermediate motion.

Safety

Evidence reads are GET-only and carry no motion authority. All adapter writes still flow through Leash; zero-motion heartbeats only seal the current interval and do not issue motor commands.

Validation

• cargo test --all-targets (158 tests)
• cargo clippy --all-targets --no-deps -- -D warnings
• cargo check --no-default-features --features sim,http,mcp,waveshare-ugv,bridge-compat,physical-navigation,v4l2-camera,webrtc

Closes #190