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/3bec6b84391a4004b115d7d4f1a2e193/metadata.json

@@ -46,5 +46,26 @@
     "public": true,
     "publish": true,
     "skipped_files": []
-  }
+  },
+  "source_format": "easyeda-std",
+  "source_path": "source/",
+  "source_documents": [
+    {
+      "doc_uuid": "c2615aa9ba064507bbfadd9ab66f94b4",
+      "docType": 1,
+      "master": "e43a0412c3aa4f409701e25c661917d2",
+      "path": "source/c2615aa9ba064507bbfadd9ab66f94b4.json",
+      "size": 110289,
+      "sha256": "86e3156ed9caf79b79ad12294ce7a370889c06a256ce3d7a582f8c1022a4674f"
+    },
+    {
+      "doc_uuid": "d6d54718030b4ae9abf7f4037a790197",
+      "docType": 3,
+      "master": "a6579c776f954aec9e45fde609e4216d",
+      "path": "source/d6d54718030b4ae9abf7f4037a790197.json",
+      "size": 714573,
+      "sha256": "e198a75627be45c4de0ca0257e7deba408be735071208ade6fe077714c140d1e"
+    }
+  ],
+  "editor_version": "6.5.1"
 }