Against a legacy (no-TTL) host, a held Deck rumble droned forever if the stop
datagram was lost: the 40 ms keep-alive re-kicked the actuator indefinitely and
only the v2 lease `deadline` ever bounded it. Add a per-slot `updated_at` clock
bumped ONLY by real host datagrams (never by the keep-alive re-kick, unlike
`last_at`), and in the legacy branch (`ttl_ms == 0`) issue a single (0, 0) once
it is stale past LEGACY_RUMBLE_CEILING_MS (1000 ms = 2x the host's flat 500 ms
legacy refresh). A genuinely-held legacy rumble refreshes every 500 ms and never
trips; the v2 `deadline` path is untouched and stays authoritative.
Verified: Windows .173 `cargo clippy -p pf-client-core -- -D warnings` (green).
On-glass owed: real Deck with an induced legacy stop-frame drop.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
enricobuehler
aedffc69dd