## Why
A delegate bound at session creation cannot provide different callbacks for cells sharing that session. Each execution needs to retain its own delegate across yields and release it when the cell is cleaned up.
## What changed
- Pass `CodeModeSessionDelegate` to `execute` instead of session creation.
- Route tool calls, notifications, and cell closure callbacks through the execution's delegate in the in-process runtime and the gRPC and stdio transports.
- Retain delegates with pending executions and live cells, releasing them through closure and cancellation cleanup.
## Testing
Add coverage for distinct delegates across yielded cells, gRPC callbacks before cell admission, and delegate release after completion or abandoned execution cleanup. Update transport tests to verify callbacks reach the owning cell's delegate.
GitOrigin-RevId: 7469f52104b993e790a40c65fb800ad02b7fd606
## What changed
- Inject W3C `traceparent` metadata into code-mode session and execution requests.
- Carry each execution's trace context on streamed tool callbacks so callback and nested-tool spans remain connected across the gRPC boundary.
- Preserve the relevant spans when execution, callback, and dispatch work moves into spawned tasks.
GitOrigin-RevId: 6482963cb9b2e2f0ea27f1345bba208b70a80d0b
## What changed
- Forward notification text to the session delegate without applying the previous 1,024-byte limit or appending a truncation suffix.
- Update the gRPC host integration test to verify that oversized multibyte notification text is delivered unchanged.
GitOrigin-RevId: 9a9e24b359a07540f70ec4e98b28524db3f7a4a0
## What changed
- Subscribe each gRPC code-mode session to nested tool calls and forward tool and notification callbacks to its delegate.
- Complete tool calls through the host while bounding oversized results and errors.
- Track callback ownership and cancellation so completed cells drain notifications, terminated cells cancel them, and shutdown revokes outstanding work.
- Validate callback identifiers, cell ownership, enabled tools, and pending callback limits without serializing independent callbacks or sessions.
## Testing
- Add integration and state tests for callback forwarding, completion ordering, cancellation, malformed callbacks, delegate panics, oversized results, and concurrent work.
GitOrigin-RevId: 005afbb90eea0eb77d746b930a1a96ca6dfcd4e7
## What changed
- Add `GrpcCodeModeSessionProvider` for opening code-mode sessions over HTTP/2 or an existing `tonic` channel.
- Support execution, waiting, termination, per-session limits, cell-closure callbacks, and graceful shutdown over the gRPC protocol.
- Bound transport waits and error messages, validate host identifiers and responses, and clean up abandoned executions and observers.
## Testing
- Add end-to-end TCP tests covering session persistence, cancellation, concurrent waits, shutdown, cell cleanup, and independent yield limits.
- Add unit coverage for protocol conversion, deadlines, and session lifecycle state.
GitOrigin-RevId: d4729ce608ad4b42a99744b07e1f230e46cb24ec
Abhinav