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/a76c7d50a6c345628eae36dfa7d40541/metadata.json

@@ -36,5 +36,26 @@
     "public": true,
     "publish": true,
     "skipped_files": []
-  }
+  },
+  "source_format": "easyeda-std",
+  "source_path": "source/",
+  "source_documents": [
+    {
+      "doc_uuid": "5e0e1dddeb5546f99463dd50b39a9d6d",
+      "docType": 1,
+      "master": "f93e24c7b22e4f278bd24734b169566b",
+      "path": "source/5e0e1dddeb5546f99463dd50b39a9d6d.json",
+      "size": 435316,
+      "sha256": "16219e061840b5f9fc8011fd41982ec9ac6bbe9c6d86778aa866f8b7a70ffd26"
+    },
+    {
+      "doc_uuid": "8cfb842513e345ccb57652110550f217",
+      "docType": 3,
+      "master": "78a1abcd5114472b8a847ebd5c4430a7",
+      "path": "source/8cfb842513e345ccb57652110550f217.json",
+      "size": 1108425,
+      "sha256": "9807cfe9924cb1b324d237f7b01981ae26ac9315ae58ced389797b65c5577270"
+    }
+  ],
+  "editor_version": "6.3.43"
 }