fix: update services.py rates to match new thermald/gpsd publish rates

Root cause of "TAKE CONTROL IMMEDIATELY / Communication Issue Between
Processes" during driving: our 4Hz thermald and 2Hz gpsd changes pushed
deviceState, managerState, and gpsLocation above their declared rate
ceilings in cereal/services.py. SubMaster's freq_ok check requires
observed rate within [0.8*min, 1.2*max]; publishing faster than max also
fails the check — which trips all_freq_ok(), raises EventName.commIssue,
and fires the banner.

- deviceState: 2Hz → 4Hz  (matches thermald DT_TRML=0.25)
- gpsLocation: 1Hz → 2Hz  (matches gpsd 2Hz polling)
- managerState: 2Hz → 4Hz (gated on deviceState arrival, inherits rate)

Also:
- Re-enabled dashcamd in process_config.py (was disabled for the
  diagnostic test — dashcamd was innocent).
- Added a CLAUDE.md section documenting this class of bug so the next
  rate change updates services.py too.

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

CLAUDE.md

@@ -84,6 +84,31 @@ ls /data/log2/current/
 cat /data/log2/current/gpsd.log
 ```
 
+### Changing a Service's Publish Rate
+
+SubMaster's `freq_ok` check requires observed rate to fall within
+`[0.8 × min_freq, 1.2 × max_freq]` of the value declared in
+`cereal/services.py`. Publishing *faster* than declared fails the check
+just as surely as publishing too slowly — it trips `all_freq_ok()` →
+`EventName.commIssue` → "TAKE CONTROL IMMEDIATELY / Communication Issue
+Between Processes".
+
+If you change how often a process publishes, you **must** update the rate
+in `cereal/services.py` to match. Example (real bug we hit):
+
+- Bumped thermald from 2Hz → 4Hz (DT_TRML 0.5→0.25) for faster fan control
+- Bumped gpsd from 1Hz → 2Hz
+- manager publishes `managerState` gated by `sm.update()` returning on
+  `deviceState`, so it picks up thermald's rate automatically
+
+`services.py` still declared `deviceState` and `managerState` as 2Hz
+(ceiling 2.4Hz) and `gpsLocation` as 1Hz (ceiling 1.2Hz), so controlsd
+fired `commIssue` on every cycle the moment any of these arrived at the
+new faster rate.
+
+Fix: update the second tuple element (Hz) in `cereal/services.py` for the
+affected service. Cereal will use the updated rate for all consumers.
+
 ### Adding New Params
 
 The params system uses a C++ whitelist. Adding a new param name in `manager.py` alone will crash with `UnknownKeyName`. You must: