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/201d355452dc48d988f0ddbd981a8a4d/metadata.json

@@ -46,5 +46,34 @@
     "public": true,
     "publish": true,
     "skipped_files": []
-  }
+  },
+  "source_format": "easyeda-std",
+  "source_path": "source/",
+  "source_documents": [
+    {
+      "doc_uuid": "0a8dab289f0e4561a664ec24654e0d08",
+      "docType": 1,
+      "master": "93d3b521d9ad4503b2684eab80afb229",
+      "path": "source/0a8dab289f0e4561a664ec24654e0d08.json",
+      "size": 148604,
+      "sha256": "ea3bc372a4df1b4cbda2013bb5babefdb6c65eaa6bf4a7d6b4ac6ed5dd8b20d0"
+    },
+    {
+      "doc_uuid": "ecf5458c25b34a44a7d954b542088f1f",
+      "docType": 3,
+      "master": "4f8753ae1f0c4f8da0773fa4ec81e0b1",
+      "path": "source/ecf5458c25b34a44a7d954b542088f1f.json",
+      "size": 1005604,
+      "sha256": "d9808260efdf6582cb748c3e3718710bcb6e98f34db8356abe2f4f4733b3acd9"
+    },
+    {
+      "doc_uuid": "13889775db9f482f834d0bdea66b3be8",
+      "docType": 3,
+      "master": "a8e508fa68234e2db1a54a1f2a99c337",
+      "path": "source/13889775db9f482f834d0bdea66b3be8.json",
+      "size": 346518,
+      "sha256": "2038c452a96dc21218cb5f694da5231a12b349e24604d7d5b0fbbc528cd1f139"
+    }
+  ],
+  "editor_version": "6.4.30"
 }