اضافه شدن قابلیت share و نگهداری بلندمدت

README.md

@@ -114,7 +114,7 @@ Full settings, credentials, optional encryption, migration instructions and the
 | `PUBLIC_BASE_URL` | `http://127.0.0.1:8000` |
 | `MAX_UPLOAD_BYTES` | 33,554,432 (32 MiB) |
 | `PARSE_TIMEOUT_SECONDS` | 60 wall-clock seconds |
-| `LINK_TTL_SECONDS` | 604,800 (7 days), maximum accepted `expires_in` |
+| `LINK_TTL_SECONDS` | 604,800 (7 days), finite default/maximum; `expires_in=-1` disables expiry |
 | `MAX_PENDING_JOBS` | 100 active/unexpired jobs |
 | `FONT_DIR` | Unset; optional administrator-managed webfont directory |
 
@@ -155,3 +155,5 @@ The fixture downloader checksum-pins an actual upstream KiCad SchDoc. Unit-test
 ## Architecture and PCB extension
 
 See [architecture](docs/ARCHITECTURE.md). `app/documents.py` is the parser registry, the schema preserves source records separately from vector primitives, `app/render.py` is the SVG serializer, and workers/storage are independent of schematic record decoding. Native PCB support uses separate `POST /api/v1/pcbs/render` and `POST /api/v1/pcbs/comparisons` endpoints, with layer-aware fullscreen viewers and structural comparison. Existing SchDoc endpoints remain unchanged and reject PCB uploads. See [PCB API, supported format subset and deployment](docs/PCB.md).
+
+All upload operations accept `expires_in=-1` for unlimited retention. Upload results and viewers offer Share with a copyable iframe snippet, including a private read token when needed. See [expiry and embedding](docs/API.md#unlimited-links-and-embedding).