Document no-SDK EventLab trial and broader input proposals

[elkampu]

Summary

• document the verified self-contained EventLab workflow for Windows and Linux
• add a no-code path for Frigate and ONVIF behavior reports
• add a bounded issue form for proposing other documented camera-event input families
• record the unreleased onboarding changes

Verification

• downloaded and extracted the published Windows x64 alpha bundle
• bundled verify passed all 4 cases
• bundled replay --no-wait produced 3 deterministic events
• dotnet test OpenCamInterop.sln --configuration Release --no-restore: 47 passed
• dotnet format OpenCamInterop.sln --verify-no-changes --no-restore
• git diff --check

This is maintainer-authored onboarding work. It does not change external contribution, adoption, or compatibility metrics.