feat: dashcamd trip lifecycle, status indicator, CLAUDE.md updates

dashcamd now waits for valid system time + GPS fix + drive gear before
starting a trip. Returns to waiting state on 10-min park timeout or
ignition off. Publishes DashcamState and per-trip DashcamFrames to
memory params. Status window shows stopped/waiting/recording states.

Updated CLAUDE.md with current display mode behavior, OmxEncoder port
details, speed limit warning thresholds, and dashcam param docs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

common/params.cc

@@ -111,6 +111,7 @@ std::unordered_map<std::string, uint32_t> keys = {
     {"CurrentRoute", CLEAR_ON_MANAGER_START | CLEAR_ON_ONROAD_TRANSITION},
     {"DashcamDebug", PERSISTENT},
     {"DashcamFrames", PERSISTENT},
+    {"DashcamState", PERSISTENT},
     {"DashcamShutdown", CLEAR_ON_MANAGER_START},
     {"DisableLogging", CLEAR_ON_MANAGER_START | CLEAR_ON_ONROAD_TRANSITION},
     {"DisablePowerDown", PERSISTENT},