## Why
Detached work can keep request spans open beyond response enqueueing. Record explicit phase timings to distinguish request handling from the full span lifetime.
## What changed
- Record server dispatch and response enqueue offsets from request receipt, plus a response enqueue event for HTTP responses that bypass the dispatcher.
- Emit client request enqueue and response receipt events, including success or server-error outcomes and reader-to-caller delay. Carry completion timestamps to the awaiting task so receipt events retain its tracing context.
- Add spans for process startup, sandbox preparation, shell snapshot preparation and capture, and process spawning. Record process identifiers only when nonempty and at most 64 bytes long.
GitOrigin-RevId: 237db898b3284fe8a6a36cb0055b3c7991d8e8a4
## Why
Exec-server process and network-policy events need stable attribution to the
launching tool call and executor without recording process payloads.
## What changed
- Add optional `ExecMetadata` to `ExecParams` and propagate the thread and tool
call IDs from unified exec.
- Emit bounded OpenTelemetry events for process start, spawn failure, sandbox
denial, and exit. Correlate them with the launch trace and registry-issued
executor identity while excluding arguments, paths, environment values,
output, and error text.
- Preserve launch attribution across long-running processes and reconnects, and
attach the same metadata to network-policy audit events.
- Keep the protocol backward compatible when metadata is omitted, and prevent
invalid trace headers from inheriting an unrelated active span.
## Testing
Add coverage for metadata serialization and propagation, lifecycle event
fields, trace relationships, reconnect behavior, spawn failures, sandbox
denials, and network-policy attribution.
GitOrigin-RevId: 7aa480a7289c73cb95e2c124c35500bb6f0d5084
Adam Perry @ OpenAI