batch-50: Step 3-4 source download from Guangzhou — 49/50 ok

Run on dev1 (Guangzhou) for the latency advantage. Walltime 3:41 vs
Singapore-estimated 1-2h (~30x speedup, mostly from image.lceda.cn
RTT going from 263ms to 2.6ms).

Pro 25:  24 ok + 1 fail (Super Dial 7f7565ef11 — Pro 2.x legacy
                          schematic/lists 401, separate cookie-perm issue)
         611 docs, 31 MB total
Std 25:  25 ok, 97 docs, 74 MB total
Combined: 49/50 success, 708 docs, 105 MB new disk usage

--max-source-mb 200 cap was not tripped; the 25 Pro candidates are all
under 10 MB, so the 481 MB X86-board outlier from the original sample
was not representative.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

data/raw/oshwhub/e5dc20d57ef243b985ff86c12a46135c/metadata.json

@@ -91,5 +91,26 @@
     "public": true,
     "publish": true,
     "skipped_files": []
-  }
+  },
+  "source_format": "easyeda-std",
+  "source_path": "source/",
+  "source_documents": [
+    {
+      "doc_uuid": "52804e1706aa4db09665e62024bbf397",
+      "docType": 1,
+      "master": "855218176dc445fc9d7ae3d9a4e582fe",
+      "path": "source/52804e1706aa4db09665e62024bbf397.json",
+      "size": 299978,
+      "sha256": "d4a63fbaf7ce79b26e06c601a4f234f3d6c86a0e0dbe8fd9240239df5f63327c"
+    },
+    {
+      "doc_uuid": "5a658da636174944aa0f7485252a3990",
+      "docType": 3,
+      "master": "6c1c9b3ce01e4c68abda0a4438105d2a",
+      "path": "source/5a658da636174944aa0f7485252a3990.json",
+      "size": 1252715,
+      "sha256": "98f99f06109f8e6ad064a21bb093bfe0119467e62aa0d5f1d988f500733af166"
+    }
+  ],
+  "editor_version": "6.5.29"
 }