fix(battery): keep CP-087 stores through R8, Diagnostics stops crashing

BatteryDigestStore and AdviceJournal persist with Gson but had no keep
rule. The minified build lost the envelopes' generic signatures, Gson
returned LinkedTreeMap entries, and the Diagnostics report threw a
ClassCastException as soon as a digest existed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: malys

CHANGELOG.md

@@ -81,6 +81,10 @@ All notable changes follow [Keep a Changelog](https://keepachangelog.com/en/1.1.
 
 ### Fixed
 
+- **The Diagnostics page opens again on a release build.** The battery digest and the advice
+  history (CP-087) were saved with Gson but had no keep rule, so the minified build read their
+  entries back as maps and the report crashed as soon as a digest existed. Files written by the
+  broken build are set aside once and a new history starts.
 - **The eco voice can be heard, and checked.** The coach now waits for the vehicle voice service
   to bind before speaking instead of asking it in the same instant it starts binding, and speaks
   on its own worker thread. Turning the voice on says a test line at once; if neither the car's

app/proguard-rules.pro

@@ -36,3 +36,14 @@
 # where the capture and the trip history read fine. A validation drive costs a drive.
 -keep class com.evsuite.chargepilot.ValidationArtifact { *; }
 -keep class com.evsuite.chargepilot.ValidationArtifact$Answer { *; }
+
+# CP-087's two stores, left out like CP-055's artifact was. Unkept, R8 dropped the generic
+# signature of each envelope's list, Gson read the entries back as maps, and the first one
+# touched threw a ClassCastException: the Diagnostics page died as soon as a digest existed.
+# The enums are kept too, since their persisted names are the schema.
+-keep class com.evsuite.hardware.telemetry.BatteryDigest { *; }
+-keep class com.evsuite.hardware.telemetry.BatteryDigestStore$Envelope { *; }
+-keep class com.evsuite.hardware.telemetry.CalibrationVerdict { *; }
+-keep class com.evsuite.chargepilot.AdviceEntry { *; }
+-keep class com.evsuite.chargepilot.AdviceKind { *; }
+-keep class com.evsuite.chargepilot.AdviceJournal$Envelope { *; }