## What changed
Add `record_global_operation` to record an operation count and duration in milliseconds, buffering up to 256 pairs until a metrics provider is installed. Validate both metric names and tags before accepting a pair, limit each operation to 16 tags and 1024 bytes of metadata, and drop whole pairs when the buffer is full.
Drain pending operations on installation and serialize recording with provider lifecycle changes so a pair stays with one installation. Resume buffering when the active provider shuts down without disturbing a newer installation. Disabling metrics discards pending operations and suppresses recording until metrics are enabled again.
## Testing
Add unit and integration coverage for buffer limits, validation, concurrent installation and replacement, redirected global handles, shutdown buffering, and accepted or rejected opt-out configuration changes.
GitOrigin-RevId: 3b094e69bf975016ff1fb8f99b3611c2ccddccf3
Celia Chen
0ed77c274b