## What
Server should request:
```
{
"id": 42,
"method": "currentTime/read",
"params": {
"threadId": "11111111-1111-1111-1111-aaaaafdc2c11"
}
}
```
Client should respond with something like:
```rust
{
"id": 42,
"result": {
"currentTimeAt": 1781717655
}
}
```
## Why
Sessions configured with `clock_source = "external"` need a
thread-specific external time source before inference. The system clock
remains the default production provider.
## Validation
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-app-server --test all
current_time_read_round_trip_adds_reminder_to_model_input`
- `cargo test -p codex-app-server
first_attestation_capable_connection_for_thread_only_uses_thread_subscribers`
- `cargo test -p codex-analytics`
- `just fix -p codex-app-server-protocol`
- `just fix -p codex-app-server`
Stacked on #28824.
rka-oai