This is a comment left during a code review.
Path: internal/processing/pause_resume.go
Line: 90-95

Comment:
**"What" comments should explain "why"**

Two inline comments in this file label *what* the code does without explaining *why* it must work that way:

`// Guard: still transitioning to paused` (line 90) doesn't explain the failure mode being avoided — that `ExtractPausedConfig` returns `nil` while the worker is mid-shutdown, so without this guard the call would silently fall through to a cold-path resume, potentially enqueuing a duplicate config or losing the in-memory byte progress.

`// Mechanical cancel via pool` (line 245) doesn't explain the ordering rationale — that the pool is cancelled first because it holds the live context and in-memory state, and the DB is queried afterwards to supplement metadata for downloads that may have no live pool entry at all.

Suggested rewrites:
```go
// Reject the resume if the worker is still mid-shutdown: ExtractPausedConfig
// would return nil, and we would fall through to a cold-path re-enqueue that
// either errors or silently duplicates the in-flight download.
```
```go
// Cancel the live pool entry first: the pool holds the running context and
// in-memory state. We then query the DB to fill in identity fields for
// downloads that are DB-only (paused in a prior session) or already completed.
```

**Rule Used:** What: Comments must explain *why* code exists, not... ([source](https://app.greptile.com/review/custom-context?memory=4e45ef13-32c2-4753-8060-a44ef767144d))

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: internal/processing/manager_test.go
Line: 911-964

Comment:
**Missing test: `UpdateURL` without a pool hook**

Both existing `UpdateURL` tests always wire `hooks.UpdateURL`. The second branch in `LifecycleManager.UpdateURL` — when `hooks.UpdateURL == nil` — calls `state.UpdateURL` directly (the DB-only path, for downloads that have no live pool entry). This path is reachable in production for cold/DB-only downloads and is not covered by any test.

A minimal addition:
```go
func TestLifecycleManager_UpdateURL_DBOnlyPath(t *testing.T) {
    tempDir := testutil.SetupStateDB(t)
    testutil.SeedMasterList(t, types.DownloadEntry{
        ID:       "db-only-id",
        URL:      "http://example.com/old.zip",
        URLHash:  state.URLHash("http://example.com/old.zip"),
        DestPath: filepath.Join(tempDir, "file.zip"),
        Filename: "file.zip",
        Status:   "paused",
    })

    mgr := newLifecycleManagerForTest()
    // No UpdateURL hook — exercises the DB-only path.
    mgr.SetEngineHooks(EngineHooks{})

    if err := mgr.UpdateURL("db-only-id", "http://example.com/new.zip"); err != nil {
        t.Fatalf("UpdateURL (DB-only path) failed: %v", err)
    }
    entry, err := state.GetDownload("db-only-id")
    if err != nil || entry == nil || entry.URL != "http://example.com/new.zip" {
        t.Errorf("DB URL not updated: %v", err)
    }
}
```

**Rule Used:** What: All code changes must include tests for edge... ([source](https://app.greptile.com/review/custom-context?memory=2b22782d-3452-4d55-b059-e631b2540ce8))

How can I resolve this? If you propose a fix, please make it concise.