diff --git a/docs/memory/feature-flows.md b/docs/memory/feature-flows.md
index a3f8f6caa..7b00ded58 100644
--- a/docs/memory/feature-flows.md
+++ b/docs/memory/feature-flows.md
@@ -12,6 +12,7 @@
 | Date | ID | Feature | Flow |
 |------|-----|---------|------|
 | 2026-04-24 | WEBHOOK-001 (#291) | Webhook triggers — token-authenticated public URL fires schedule executions | [webhook-triggers.md](feature-flows/webhook-triggers.md) |
+| 2026-04-25 | #496 | Backlog drain spawn fix — repair `_spawn_drain` lazy import after #95 renamed `_execute_task_background` → `_run_async_task_with_persistence`; AST-based regression tests pin the contract | [persistent-task-backlog.md](feature-flows/persistent-task-backlog.md) |
 | 2026-04-25 | #487 | Telegram file upload Phase 2 — workspace delivery hardening: NFKC sanitizer with collision dedup, spec injection format `[File uploaded by {uploader}]: {name} ({size}) saved to {path}`, all-writes-failed channel error + abort. Same code path benefits Slack inbound. | [telegram-integration.md](feature-flows/telegram-integration.md), [slack-file-sharing.md](feature-flows/slack-file-sharing.md) |
 | 2026-04-23 | #476 | SQLite lexicographic cutoff bug fix — new `iso_cutoff(hours)` helper replaces `datetime('now', ...)` in 15 sites across rate-limit / dashboard / schedules; `max_retries` default flipped `1 → 0`; `cleanup_old_rate_limit_events` wired into `CleanupService` (phase 6, hourly) | [subscription-auto-switch.md](feature-flows/subscription-auto-switch.md), [cleanup-service.md](feature-flows/cleanup-service.md), [scheduler-service.md](feature-flows/scheduler-service.md) |
 | 2026-04-22 | #458 | `.gitignore` init fix — `initialize_git_in_container` now appends missing patterns instead of truncate-and-write; adds `.env`, `.env.*`, `.mcp.json` to the default list and runs for both `/home/developer` and legacy `/home/developer/workspace` (stops credential leak on first GitHub sync) | [github-repo-initialization.md](feature-flows/github-repo-initialization.md) |
diff --git a/docs/memory/feature-flows/parallel-capacity.md b/docs/memory/feature-flows/parallel-capacity.md
index 5f6d6aa8e..3abdd730e 100644
--- a/docs/memory/feature-flows/parallel-capacity.md
+++ b/docs/memory/feature-flows/parallel-capacity.md
@@ -61,8 +61,8 @@ The frontend displays slot usage as a vertical capacity meter bar on the Agents
 │  │  1. Create execution record in database (chat.py:602-613)       │     │
 │  │  2. Router acquires slot directly (chat.py:644-651)             │     │
 │  │  3. If full → 429 response (chat.py:653-663)                   │     │
-│  │  4. Spawn _run_async_task_with_persistence() with release_slot=True     │     │
-│  │  5. Background task releases slot in finally (chat.py:554-557)  │     │
+│  │  4. Spawn _run_async_task_with_persistence() (router pre-acquired)│    │
+│  │  5. TaskExecutionService releases slot in finally (slot_already_held=True)│
 │  │                                                                  │     │
 │  │  PUBLIC path (public.py:315-322 → task_execution_service.py):   │     │
 │  │  1. Delegate to TaskExecutionService.execute_task()              │     │
@@ -137,7 +137,7 @@ POST /api/agents/{name}/task  (async)
   │ 1. db.get_max_parallel_tasks(name)              │
   │ 2. slot_service.acquire_slot(...)               │
   │ 3. If not acquired → 429 Too Many Requests     │
-  │ 4. Spawn background task with release_slot=True │
+  │ 4. Spawn `_run_async_task_with_persistence()`   │
   └─────────────────────────────────────────────────┘
 ```
 
diff --git a/docs/memory/feature-flows/task-execution-service.md b/docs/memory/feature-flows/task-execution-service.md
index 418302c77..fd596ec22 100644
--- a/docs/memory/feature-flows/task-execution-service.md
+++ b/docs/memory/feature-flows/task-execution-service.md
@@ -58,7 +58,7 @@ Callers inspect `result.status` to decide HTTP response. Status values come from
 
 Moved from `routers/chat.py`. Module-level async function. Used by:
 - `TaskExecutionService.execute_task()` internally (line 249)
-- `routers/chat.py` for `/chat` endpoint (line 248) and `_execute_task_background` (line 477)
+- `routers/chat.py` for `/chat` endpoint and `_run_async_task_with_persistence` (the async-mode wrapper introduced by #95; previously named `_execute_task_background`)
 
 ```python
 async def agent_post_with_retry(
@@ -163,7 +163,7 @@ The endpoint handles:
 2. Determine `triggered_by` from headers (lines 686-691)
 3. Create execution record early (lines 694-705) -- passed to service as `execution_id`
 4. Collaboration tracking for agent-to-agent (lines 710-732) -- stays in router
-5. **Async mode branch** (lines 735-808) -- spawns `_execute_task_background()`, does NOT use service
+5. **Async mode branch** -- pre-acquires capacity slot, then spawns `_run_async_task_with_persistence()` which delegates to `task_execution_service.execute_task(slot_already_held=True)` (post-#95)
 6. **Sync mode branch** (lines 810-827) -- delegates to `task_execution_service.execute_task()`
 7. Collaboration activity completion (lines 830-839)
 8. Error translation to HTTP exceptions (lines 842-857)