-- Dedup analyze_page jobs in flight (mirrors 0014 for sync_chapter_content).
--
-- Without this, `repo::page_analysis::enqueue_pages`' `NOT EXISTS(... pending
-- | running ...)` read-then-insert race let concurrent admin POSTs land
-- duplicate jobs for the same page — visible as duplicate "now analyzing"
-- SSE events and inflated `pending` counters in the admin dashboard, even
-- though the worker's `skip-if-done` net (analysis/daemon.rs:210-217)
-- prevented the actual duplicate vision call.
--
-- The partial unique index lets enqueue_pages drop the NOT EXISTS subquery
-- and rely on `ON CONFLICT DO NOTHING` instead. At most one (pending|running)
-- job per page_id can exist; the slot frees the moment the job transitions
-- to done/failed/dead, so a force re-analyze still re-enqueues cleanly.
CREATE UNIQUE INDEX crawler_jobs_analyze_page_dedup_idx
    ON crawler_jobs ((payload->>'page_id'))
 WHERE state IN ('pending', 'running')
   AND payload->>'kind' = 'analyze_page';