飞控-77: 77 std flight-controller projects ingested

Topic-targeted pull from local listing index (`name OR introduction`
contains 飞控). 79 std hits in oshwhub_listing_full.jsonl, 2 already
crawled, 77 newly fetched.

dev1 (Guangzhou) walltime:
  Step 1 detail scrape ~12s, Step 4 std-source backfill ~80s
  (concurrency=5)
Source completeness: 73/77 with editor source, 4 are upstream
attachments-only (no editor session ever attached, source_documents=[]
is genuine — no editor_version on the SSR page either).

Crawler hardening (crawlers/oshwhub/crawler.py):
- count.{like,star,fork,views} are now `.get(..., 0)` defensive.
  Listing API omits zero-valued fields for some low-activity entries
  (3/77 hit this on first pass, hard-failed with KeyError 'like').
  Affects rank_score, pick_top, and metadata.json metrics block.

License mix: 65% GPL 3.0, 11% Public Domain, 11% MIT, ~6% CC variants.

Transport: dev1 → SG via tar+scp (33 MB, ~3 min over lossy
cross-region link). Bypassed gitea push from dev1 because the same
6.5%-loss link tanks single-stream throughput.

data/raw/oshwhub/21817f8fcf2d4e36b96f8e00c33a5c93/source/manifest.json

@@ -0,0 +1,35 @@
+{
+  "project_uuid": "21817f8fcf2d4e36b96f8e00c33a5c93",
+  "fetched_at": "2026-04-30T10:57:08.684279+00:00",
+  "editor_version": "6.4.31",
+  "documents": [
+    {
+      "doc_uuid": "e7d66b9e02b9457083f9ab563784a0f2",
+      "docType": 3,
+      "master": "d158f8681c8943c9b7ae993a21d3573b",
+      "path": "source/e7d66b9e02b9457083f9ab563784a0f2.json",
+      "size": 567060,
+      "sha256": "d5a7011ab048898e86cff342f8ea21f640beb0878917ca5fdae64938f97662a9"
+    }
+  ],
+  "upstream_version_documents": [
+    {
+      "uuid": "e7d66b9e02b9457083f9ab563784a0f2",
+      "title": "M1_MH742_Adaptor_V43_ASC.PcbDoc",
+      "description": "",
+      "docType": 3,
+      "master": "d158f8681c8943c9b7ae993a21d3573b",
+      "thumb": "//image.lceda.cn/histories/d158f8681c8943c9b7ae993a21d3573b.png",
+      "components": {
+        "a29ba53807cf43cab02f2f8a6393998d": 2,
+        "df6becfa9964479e9d9250ab07a23ecc": 2
+      },
+      "updateTime": 1643941579,
+      "createTime": 1643941540,
+      "histories": [
+        "6009255517744ad5a113232591f976ad",
+        "d158f8681c8943c9b7ae993a21d3573b"
+      ]
+    }
+  ]
+}