Pick up the AgentGraphStore migration.
- Inject an explicit optional agent graph store into `ThreadManager`
- Move all calls to spawn, close, recursive resume, and
subtree/archive/delete/feedback traversal through it
- Keep using `LocalAgentGraphStore` when SQLite is available
This required some changes to the interface to deal with futures:
- The interface now matches `ThreadStore`'s object-safe pattern by
returning a boxed `AgentGraphStoreFuture` directly, allowing
`ThreadManager` to hold `Arc<dyn AgentGraphStore>`
*Slight behavior change!* Unfiltered subtree enumeration now performs a
single all-status breadth-first traversal, so a closed grandchild
beneath an open edge is included; the previous Open-then-Closed
traversals could not cross mixed-status paths and silently omitted it.
## Why
First-party async traits should expose their `Send` contracts explicitly
without requiring `async_trait`. This completes the migration pattern
established in #27303 and #27304.
## What changed
- Replaced the remaining first-party `async_trait` traits with native
return-position `impl Future + Send` where statically dispatched and
explicit boxed `Send` futures where object safety is required.
- Kept implementations behavior-preserving, outlining existing async
bodies into inherent methods where that keeps the diff reviewable.
- Removed all direct first-party `async-trait` dependencies and the
workspace dependency declaration.
- Added a cargo-deny policy that permits `async-trait` only through the
remaining transitive wrapper crates.
- Updated `rand` from 0.8.5 to 0.8.6 to resolve RUSTSEC-2026-0097 and
keep the full cargo-deny check passing.
## Validation
- `just test -p codex-exec-server`: 216 passed, 2 skipped.
- `just test -p codex-model-provider`: 39 passed.
- `just test -p codex-core` and `just test`: changed tests passed;
remaining failures are environment-sensitive suites unrelated to this
migration.
- `cargo deny check`
- `just fix`
- `just fmt`
- `cargo shear`
- `just bazel-lock-check`
## Summary
Persisted subagent parent/child topology currently leaks through
`StateRuntime`'s SQLite-specific thread-spawn helpers. This PR
introduces a narrow `AgentGraphStore` boundary so follow-up work can
route graph operations through a local or remote store without coupling
orchestration code directly to the state DB graph API.
## Changes
- Adds the new `codex-agent-graph-store` crate.
- Defines a flat `AgentGraphStore` trait for the v1 graph surface:
upsert edge, set edge status, list direct children, and list
descendants.
- Adds public graph types for `ThreadSpawnEdgeStatus`,
`AgentGraphStoreError`, and `AgentGraphStoreResult`.
- Implements `LocalAgentGraphStore` on top of an existing
`codex_state::StateRuntime`, preserving today's SQLite-backed
`thread_spawn_edges` behavior.
- Registers the crate in Cargo/Bazel metadata.
This PR only adds the local contract and implementation; call-site
migration and the remote gRPC store are left to the follow-up PRs in the
stack.
## Testing
- `cargo test -p codex-agent-graph-store`
The new unit tests cover local parity with the existing `StateRuntime`
graph methods, `Open`/`Closed` filtering, status updates, and stable
breadth-first descendant ordering.
TomandGitHub
Adam Perry @ OpenAIandGitHub
Rasmus RygaardandGitHub