Make the event detector a CAM rate input, not a ride-stats readout

The detector's only live consumer is the CAM transmit-rate policy: every
emitted event calls CamTransmitLoop.onDetectedEvent, raising the beacon
rate from 1 Hz to the elevated rate for five seconds so nearby stations
get denser updates through a manoeuvre. Counting one's own braking events
is not a goal of this project, so the display is gone and the detector
stays: the live per-type counters and their notification text, the event
pins and detail sheet on the trip review map, and the event chip on the
history card. Events are still persisted and exported to CSV, which is
the only route to the tuning measurement section 11.3 says is missing.

Fix two defects found while documenting the detector.

TripRecordingService overrode nine of DetectionConfig's twelve parameters
in its constructor, so the tests validated the Phase A defaults while the
phone ran something materially less sensitive. The tuned values are now
the defaults and the override is deleted; the numbers moved location, not
value, so detector sensitivity is unchanged. EventDetectorTest now sets
only windowSize and the sustained-frame counts and inherits every signal
threshold, which cannot drift again. That was not a free change and makes
the same point from the other side: at the real thresholds the old stimuli
triggered nothing. Accel alternating 3.5/0.5 gives a std dev of 1.5 and
never clears 1.8, and the moderate-braking case used a 0.8 m/s drop that
never clears 1.0. Those stimuli are re-derived against the real values.

brakingHighConfidenceRate was documented as a rate but has always been
compared against the peak cumulative drop from the onset speed, which
grows with episode length, so HIGH was assigned more readily than the name
implied. Renamed to brakingHighConfidencePeakDrop rather than changing the
comparison: "lost more than 1.5 m/s in one episode" is coherent, whereas a
rate off a 1 Hz speed signal sampled at 50 Hz spikes on a near-zero
divisor early in an episode. Output is unchanged, so the existing
confidence assertions stay evidence instead of being re-baselined.

Docs 11.3/11.4 updated in place, including the correction of a claim that
detected events do not reach the V2X side; the rate-bump path already
existed when that was written. 55 tests, 0 failures.

app/src/main/res/values/strings.xml

@@ -305,10 +305,6 @@
     <string name="nav_trips">Trips</string>
 
     <!-- Phase A: Recording screen event counters -->
-    <string name="rec_events_detected">Detected Events</string>
-    <string name="rec_event_braking">Braking</string>
-    <string name="rec_event_turning">Turning</string>
-    <string name="rec_event_stopping">Stopping</string>
     <string name="rec_stream_event_detection">Event Detection</string>
     <string name="rec_open_session_log">CSV Session Log</string>