modeld standby, fan standstill clamping, log rotation, diagnostic logging

- modeld standby: skip inference at standstill (model stays loaded in GPU),
  ModelStandby param + ModelStandbyTs heartbeat for race-free suppression
- controlsd: suppress commIssue/modeldLagging when ModelStandbyTs < 2s old,
  ignore telemetryd/dashcamd in process_not_running check
- Fan controller: standstill below 74°C clamps to 0-10% (near silent),
  standstill above 74°C allows 0-100%, thermald reads carState.standstill
- Deleter: enforce 4GB quota on /data/log2 session logs, oldest-first cleanup
- Diagnostic logging: steerTempUnavailable and controlsdLagging log to stderr
  with full context (steering angle, torque, speed, remaining time)
- CLAUDE.md: document memory params method name difference (C++ camelCase
  vs Python snake_case)

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

common/params.cc

@@ -198,6 +198,8 @@ std::unordered_map<std::string, uint32_t> keys = {
     {"TelemetryEnabled", PERSISTENT},
     {"Timezone", PERSISTENT},
     {"TrainingVersion", PERSISTENT},
+    {"ModelStandby", PERSISTENT},
+    {"ModelStandbyTs", PERSISTENT},
     {"UbloxAvailable", PERSISTENT},
     {"VpnEnabled", PERSISTENT},
     {"UpdateAvailable", CLEAR_ON_MANAGER_START | CLEAR_ON_ONROAD_TRANSITION},