feat(session-limits): LS3 — port Scheduler + adapter TokioScheduler

Introduit l'abstraction de planification pour la reprise différée à la
levée d'une limite de session :
- domaine : trait Scheduler + enum ScheduledTask (ports.rs), ScheduleId
  via typed_id! (ids.rs), re-exports (lib.rs).
- infra : TokioScheduler (scheduler/mod.rs, nouveau) + pub mod scheduler
  et re-export (lib.rs).

Tests QA inline (#[cfg(test)]) : 7 tests scheduler (3× sans flaky).
`cargo test -p infrastructure` = 195 passed / 0 failed ; domaine + infra
builds 0 warning ; LS1/LS2 toujours verts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/domain/src/lib.rs

@@ -65,8 +65,8 @@ mod validation;
 pub use error::DomainError;
 
 pub use ids::{
-    AgentId, LayoutId, NodeId, ProfileId, ProjectId, SessionId, SkillId, TabId, TemplateId,
-    WindowId,
+    AgentId, LayoutId, NodeId, ProfileId, ProjectId, ScheduleId, SessionId, SkillId, TabId,
+    TemplateId, WindowId,
 };
 
 pub use project::{Project, ProjectPath};
@@ -145,6 +145,6 @@ pub use ports::{
     FsError, GitCommitInfo, GitError, GitFileStatus, GitPort, GraphCommit, IdGenerator,
     MemoryError, MemoryQuery, MemoryRecall, MemoryStore, Output, OutputStream, PermissionStore,
     PreparedContext, ProcessError, ProcessSpawner, ProfileStore, ProjectStore, PtyError, PtyHandle,
-    PtyPort, RemoteError, RemoteHost, RemotePath, RuntimeError, SpawnSpec, StoreError,
-    TemplateStore,
+    PtyPort, RemoteError, RemoteHost, RemotePath, RuntimeError, ScheduledTask, Scheduler, SpawnSpec,
+    StoreError, TemplateStore,
 };