feat: notification enhancement

migrations/0034_notification_prefs.down.sql

@@ -0,0 +1,3 @@
+-- The legacy users columns were dual-written the whole time, so dropping the
+-- table loses no opt-out state that the old code paths read.
+DROP TABLE IF EXISTS notification_prefs;

migrations/0034_notification_prefs.up.sql

@@ -0,0 +1,41 @@
+-- Per-event × per-channel notification preferences.
+--
+-- One row per (user, kind, channel) the user has turned OFF. Absence of a row
+-- means enabled — the table stores opt-outs only, so new kinds/channels are
+-- enabled for everyone with no backfill, and existing users keep receiving
+-- everything they receive today.
+--
+-- `kind` is the notifications.kind machine string (follow_request, post_like,
+-- chant_reminder, …); the Settings UI groups kinds into coarser categories
+-- but storage stays kind-level so backfilled opt-outs map exactly.
+CREATE TABLE IF NOT EXISTS notification_prefs (
+    user_id    BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    kind       TEXT   NOT NULL,
+    channel    TEXT   NOT NULL CHECK (channel IN ('in_app', 'email', 'push')),
+    enabled    BOOLEAN NOT NULL DEFAULT FALSE,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    PRIMARY KEY (user_id, kind, channel)
+);
+
+-- Backfill the existing like-email opt-out at exactly its old granularity:
+-- post_like × email only (NOT the whole post-interactions category, so these
+-- users don't accidentally lose anything else).
+INSERT INTO notification_prefs (user_id, kind, channel, enabled)
+SELECT id, 'post_like', 'email', FALSE
+FROM users WHERE like_emails_enabled = FALSE
+ON CONFLICT DO NOTHING;
+
+-- Backfill the reminder opt-out: the old toggle silenced all channels at
+-- once, so it maps to every reminder kind × every channel.
+INSERT INTO notification_prefs (user_id, kind, channel, enabled)
+SELECT u.id, k.kind, c.channel, FALSE
+FROM users u
+CROSS JOIN (VALUES ('chant_reminder'), ('quote_reminder'), ('chant_incomplete_reminder')) AS k(kind)
+CROSS JOIN (VALUES ('in_app'), ('email'), ('push')) AS c(channel)
+WHERE u.sadhna_reminders_enabled = FALSE
+ON CONFLICT DO NOTHING;
+
+-- users.like_emails_enabled and users.sadhna_reminders_enabled stay for now:
+-- the prefs endpoints dual-write them so an old frontend (or a rollback)
+-- keeps working. They get dropped in a later migration once the new
+-- endpoints are fully rolled out.