Add full sortof codebase: API, drain workers, frontend, schema, specs

init/05_required_wsids_scraped_at.sql

@@ -0,0 +1,7 @@
+-- Track when we last successfully scraped a wsid's "Required Items" section.
+-- Without this, we can't distinguish "successfully scraped, zero required
+-- items" (a stable empty []) from "never scraped" (also empty {} per schema
+-- default). Backfill jobs and the missing-dep auto-resolver use it to skip
+-- already-known-empty pages.
+ALTER TABLE workshop_meta
+    ADD COLUMN IF NOT EXISTS required_scraped_at TIMESTAMPTZ;