test(ingest): use https test gateway URLs; doc fixes (review round 6)

Resolves the SonarCloud quality gate (new_security_hotspots_reviewed) — the 7
TO_REVIEW hotspots were all `http://gw` fake gateway URLs in test_ocr_processor.py
flagged "use https". Switched the test fixtures to `https://gw` (identical for a
fake URL) so no new hotspots remain to review; all other gate conditions already
passed.

Also address claude-review round 6:
- Stale test docstring: "suppresses to ocr" -> "suppresses to the cheapest
  registered OCR rung (here ocr-upstream)".
- OcrProcessor.__init__: comment that the upstream-shaped defaults are
  test/bare-construction convenience only; app wiring always passes args
  explicitly.

Left as-is (reviewer agreed): the `ocric=` signature abbreviation (opaque but
stable; renaming would invalidate dead-letter retries).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

nextcloud_mcp_server/document_processors/ocr.py

@@ -307,6 +307,10 @@ class OcrProcessor(DocumentProcessor):
 
     def __init__(
         self,
+        # The defaults describe the UPSTREAM (tier3) rung and exist for
+        # test/bare-construction convenience only. Application wiring
+        # (document_processors/__init__.py) ALWAYS passes every arg explicitly for
+        # both rungs — don't rely on these defaults in app code.
         *,
         name: str = "ocr-upstream",
         tier: str = "ocr-upstream",