feat: add streaming state storage

crates/crank-registry/src/migrations.rs

@@ -513,5 +513,72 @@ pub async fn apply_postgres(pool: &PgPool) -> Result<(), sqlx::Error> {
     .execute(pool)
     .await?;
 
+    query(
+        "create table if not exists stream_sessions (
+            id text primary key,
+            workspace_id text not null references workspaces(id) on delete cascade,
+            agent_id text null references agents(id) on delete set null,
+            operation_id text not null references operations(id) on delete cascade,
+            protocol text not null,
+            mode text not null,
+            status text not null,
+            cursor_json jsonb null,
+            state_json jsonb not null,
+            expires_at timestamptz not null,
+            last_poll_at timestamptz null,
+            created_at timestamptz not null,
+            closed_at timestamptz null
+        )",
+    )
+    .execute(pool)
+    .await?;
+
+    query(
+        "create index if not exists stream_sessions_workspace_status_idx
+         on stream_sessions(workspace_id, status, created_at desc)",
+    )
+    .execute(pool)
+    .await?;
+
+    query(
+        "create index if not exists stream_sessions_expires_at_idx
+         on stream_sessions(expires_at)",
+    )
+    .execute(pool)
+    .await?;
+
+    query(
+        "create table if not exists async_jobs (
+            id text primary key,
+            workspace_id text not null references workspaces(id) on delete cascade,
+            agent_id text null references agents(id) on delete set null,
+            operation_id text not null references operations(id) on delete cascade,
+            status text not null,
+            progress_json jsonb not null,
+            result_json jsonb null,
+            error_json jsonb null,
+            expires_at timestamptz null,
+            created_at timestamptz not null,
+            updated_at timestamptz not null,
+            finished_at timestamptz null
+        )",
+    )
+    .execute(pool)
+    .await?;
+
+    query(
+        "create index if not exists async_jobs_workspace_status_idx
+         on async_jobs(workspace_id, status, updated_at desc)",
+    )
+    .execute(pool)
+    .await?;
+
+    query(
+        "create index if not exists async_jobs_expires_at_idx
+         on async_jobs(expires_at)",
+    )
+    .execute(pool)
+    .await?;
+
     Ok(())
 }