feat: Mark database models and protobufs as stable

[jamesarich]

Mark several classes as stable for the Jetpack Compose compiler to enable optimizations. This includes Node and Message models, the Reaction entity, all Meshtastic protobuf-generated classes, and Google's ByteString.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.52%. Comparing base (f322660) to head (0d887f3).
⚠️ Report is 13 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3982   +/-   ##
=====================================
  Coverage   0.52%   0.52%           
=====================================
  Files        395     395           
  Lines      23172   23172           
  Branches    2944    2944           
=====================================
  Hits         122     122           
  Misses     23029   23029           
  Partials      21      21           

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