docs: add Bunjang cursor scraping guide

agent-workspace/domain-skills/bunjang/scraping.md

@@ -0,0 +1,57 @@
+# Bunjang search scraping
+
+## Search route
+
+Use the mobile-web search route:
+
+```text
+https://m.bunjang.co.kr/search/products?order=date&page=1&q=<url-encoded-query>
+```
+
+The `page` query parameter does not reliably expose deep results. Repeatedly changing it can return nearly the same first result set.
+
+## Cursor pagination
+
+The initial page server-renders roughly 50 product cards. Scroll to the bottom, dismiss the app-install bottom sheet via the `모바일 웹에서 볼게요` action if it appears, then click the exact `더보기` button once.
+
+That click calls:
+
+```text
+GET https://api.bunjang.co.kr/api/search/v8/web/search
+  ?q=<query>
+  &policyKey=mw.product.keyword
+  &cursor=<opaque-cursor>
+  &size=60
+```
+
+Read products from:
+
+```text
+data.responses.mainGrid.searchResponse.data[]
+```
+
+Keep entries where `type == "PRODUCT"` and `pid` exists. External ads also appear in the same array.
+
+Continue with the opaque `nextCursor` returned at:
+
+```text
+data.responses.mainGrid.searchResponse.nextCursor
+```
+
+Stop when `nextCursor` is absent. Deduplicate by `pid`; `totalCount` includes non-product and repeated entries, so it may be larger than the final unique product count.
+
+## Product details
+
+Unauthenticated product details are available at:
+
+```text
+GET https://api.bunjang.co.kr/api/pms/v3/products-detail/<pid>?viewerUid=-1
+```
+
+Important fields are under `data.product` and `data.shop`. Product images use the `imageUrl` template; replace `{cnt}` with `1..imageCount` and `{res}` with a desired width such as `840`.
+
+## Traps
+
+- Do not infer price from a whole card's concatenated text. Years, denominations, and ages can be appended to the price.
+- Do not treat a title as reliable material or authenticity evidence. Read the detail description and inspect all images.
+- A single scroll only exposes the first result set. The exact `더보기` button is the transition to cursor pagination.