Track cookie policy generation requests on publish

Add policy_document_id and policy_generation_requested_at columns to
cookie_banners and backfill banners that already have a published
version, so existing live banners get a policy on the worker's first
pass.

Flag the banner for policy generation inside the publish transaction so
generation is requested only when a cookie banner version is published,
not on draft edits. Fold policy_document_id into the existing Update so
the upcoming worker can persist the generated document id with the
scope it already holds.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/coredata/migrations/20260602T161910Z.sql

@@ -0,0 +1,27 @@
+-- Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+--
+-- Permission to use, copy, modify, and/or distribute this software for any
+-- purpose with or without fee is hereby granted, provided that the above
+-- copyright notice and this permission notice appear in all copies.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+-- REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+-- AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+-- INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+-- LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+-- OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+-- PERFORMANCE OF THIS SOFTWARE.
+
+ALTER TABLE cookie_banners
+    ADD COLUMN policy_document_id TEXT,
+    ADD COLUMN policy_generation_requested_at TIMESTAMP WITH TIME ZONE;
+
+-- Backfill: any banner that already has a published version gets its cookie
+-- policy generated on the worker's first pass.
+UPDATE cookie_banners
+SET policy_generation_requested_at = NOW()
+WHERE id IN (
+    SELECT DISTINCT cookie_banner_id
+    FROM cookie_banner_versions
+    WHERE state = 'PUBLISHED'
+);