v5 scopes forgetting to one namespace and returns the same result envelope for exact and semantic requests.

### Choose exact or semantic forgetting

| Intent | v5 operation |
| --- | --- |
| Forget reviewed memory IDs | `DELETE /ns/{namespace}/memories` |
| Find memories by meaning | `DELETE /ns/{namespace}/memories/semantic` |

### Forget exact IDs

```bash
DELETE /ns/user_1/memories
Content-Type: application/json

{"ids":["mem_1","mem_2"]}
```

Send 1–500 IDs. The response reports successful IDs in `matches` and missing or ineligible IDs in `errors`, so HTTP success does not imply every requested ID changed.

### Preview a semantic request

```bash
DELETE /ns/user_1/memories/semantic
Content-Type: application/json

{"query":"outdated home address","dryRun":true}
```

`dryRun: true` performs selection without changing memory state. `dryRun: false` forgets the memories selected when that request executes.

### Avoid selection drift

```text
semantic request with dryRun: true
                |
                v
review matches[].id
                |
                v
exact DELETE with reviewed IDs
```

Use this workflow when a human or policy must approve the exact set. Re-running the semantic request with `dryRun: false` can select a different set if memories changed after preview.

### Read the normalized response

```json
{
  "count": 1,
  "matches": [{ "id": "mem_1", "memory": "Old address" }],
  "errors": [{ "id": "mem_2", "error": "Memory not found" }]
}
```

`count` always equals `matches.length`. Both dry-run and applied semantic requests use this shape; the payload alone does not replace your record of which mode was sent.

### Removed memory-write routes

Direct v4 memory creation and version updates have no v5 replacement. Ingest source material through document routes and update the canonical document when facts change.

### Verification

- Exercise all-success, partial-success, duplicate, unknown, and cross-namespace ID sets.
- Confirm dry runs leave matched memories recallable.
- Apply reviewed IDs exactly and confirm normal recall excludes them.
- Persist the request mode alongside audit logs for semantic operations.