feat: add TreeGuardEvent proto

[jnavno]

What does this PR do?

Adds a new TreeGuardEvent message to capture battery voltage, SOC and classification results from our Tree‑Guard sensor module.

Checklist before merging

• All top level messages commented
• All enum members have unique descriptions

// TreeGuardEvent carries a snapshot of battery readings plus your
// vibration‑classification result.
message TreeGuardEvent {
// Battery voltage in volts.
float battery_voltage = 1;

// State‑of‑charge percentage (0.0–100.0).
float battery_soc = 2;

// The detected event type.
EventType event = 3;
}
…
enum EventType {
// Event could not be classified.
UNCLASSIFIED = 0;
// Likely machete impact detected.
LIKELY_MACHETE = 1;
…
}

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[thebentern]

@jnavno can you tell us a little bit about this use case? Is it for detecting illegal logging activities in protected forests? Looks really interesting

[jnavno]

Thank you for reviewing this. I've realized this pull request was opened prematurely and contains work that isn't ready for public contribution yet. I apologize for any inconvenience.

[jnavno]

@jnavno can you tell us a little bit about this use case? Is it for detecting illegal logging activities in protected forests? Looks really interesting

Thanks for your interest and question! I've closed the pull request because the content wasn't ready for public consumption or discussion. I'm not able to discuss the details further at this time, but I appreciate your understanding.