fix: backfill asset rows from script.assets for pre-feature scripts

backend/migrations/20260523091727_backfill_asset_from_script_assets.down.sql

@@ -0,0 +1,6 @@
+-- No-op: the backfill is a one-shot data migration. We can't safely
+-- distinguish backfilled rows from those a subsequent deploy inserted via
+-- the normal `insert_static_asset_usage` path (same tuple, no marker), so
+-- rolling back would risk deleting live data. Leaving the rows in place on
+-- downgrade is harmless — they'll get rewritten on the next deploy of
+-- each affected script.

backend/migrations/20260523091727_backfill_asset_from_script_assets.up.sql

@@ -0,0 +1,39 @@
+-- Backfill the `asset` table from `script.assets` JSONB for scripts that
+-- were deployed before the deploy path started populating asset rows from
+-- the parsed `ns.assets`. The JSONB column carried the parser's findings
+-- the whole time; the corresponding asset rows are what `fetch_producer_writes`
+-- (asset-trigger cascade) and the asset-graph lineage view actually query.
+-- Without this, a pre-feature script "succeeds" but the dispatcher sees
+-- no writes, no subscribers are matched, and the dispatch_event panel
+-- stays empty — exactly the gap we hit in https://… (no public link yet).
+--
+-- Idempotent: scoped to (workspace, path) pairs that have ZERO asset rows
+-- under `usage_kind = 'script'`, so re-running can't duplicate. The
+-- (workspace_id, path, kind, usage_path, usage_kind) primary key catches
+-- any residual overlap via `ON CONFLICT DO NOTHING` as a belt-and-braces.
+-- Skips archived/deleted script versions so we backfill from the *current*
+-- snapshot, matching what the live deploy path would write.
+INSERT INTO asset (workspace_id, path, kind, usage_access_type, usage_path, usage_kind)
+SELECT
+  s.workspace_id,
+  a->>'path',
+  (a->>'kind')::asset_kind,
+  (a->>'access_type')::asset_access_type,
+  s.path,
+  'script'::asset_usage_kind
+FROM script s
+CROSS JOIN LATERAL jsonb_array_elements(s.assets) AS a
+WHERE s.archived = false
+  AND s.deleted = false
+  AND s.assets IS NOT NULL
+  AND jsonb_typeof(s.assets) = 'array'
+  AND a->>'path' IS NOT NULL
+  AND a->>'kind' IS NOT NULL
+  AND NOT EXISTS (
+    SELECT 1
+    FROM asset existing
+    WHERE existing.workspace_id = s.workspace_id
+      AND existing.usage_kind = 'script'
+      AND existing.usage_path = s.path
+  )
+ON CONFLICT DO NOTHING;