Di/fix 403 logcat filters

[DaniilSmirnov]

Summary

• Normalize the UI’s single {tag, priority} Logcat filter into the repeated protobuf field expected by LogcatStartMessage.
• Preserve support for filter arrays from older clients.
• Reject malformed filter payloads gracefully instead of crashing the websocket process.
• Add unit tests for supported and invalid filter formats.
  Closes v1.5.2: при нажатии Logcat падает websocket (RangeError: Invalid array length), socket.io уходит в 502 #403
  Verification
• Focused checks for filter normalization passed.
• git diff --check passed.
• Full Vitest and TypeScript checks were not run.