feat: add stickers

migrations/0055_reward_gifts.up.sql

@@ -0,0 +1,41 @@
+-- Occasional gift rewards, granted from the admin panel.
+--
+-- A gift IS a reward grant — same catalog, same gallery, same vault — so it
+-- reuses sadhna_reward_grants rather than introducing a parallel table that
+-- every reader would then have to union in. What differs is only where it came
+-- from, which `source` records.
+--
+-- `celebrated_at` already means "the devotee has seen this", which is exactly
+-- the claim flag a gift needs: unclaimed gifts render blurred, and dismissing
+-- the celebration is what clears them.
+ALTER TABLE sadhna_reward_grants
+    ADD COLUMN IF NOT EXISTS source VARCHAR(8) NOT NULL DEFAULT 'streak';
+
+DO $$
+BEGIN
+    IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'sadhna_reward_grants_source_check') THEN
+        ALTER TABLE sadhna_reward_grants
+            ADD CONSTRAINT sadhna_reward_grants_source_check
+            CHECK (source IN ('streak', 'gift'));
+    END IF;
+END $$;
+
+-- A gift is not tied to a streak day, so it has no milestone.
+ALTER TABLE sadhna_reward_grants ALTER COLUMN milestone DROP NOT NULL;
+
+-- UNIQUE (user_id, milestone) was the streak rule: one reward per milestone.
+-- It can't police gifts, which have no milestone — so it becomes a partial
+-- index over streak rows, and gifts get their own rule: one of each reward
+-- per person, so re-gifting is idempotent rather than a duplicate tile.
+ALTER TABLE sadhna_reward_grants
+    DROP CONSTRAINT IF EXISTS sadhna_reward_grants_user_id_milestone_key;
+
+CREATE UNIQUE INDEX IF NOT EXISTS sadhna_reward_grants_streak_uniq
+    ON sadhna_reward_grants (user_id, milestone) WHERE source = 'streak';
+
+CREATE UNIQUE INDEX IF NOT EXISTS sadhna_reward_grants_gift_uniq
+    ON sadhna_reward_grants (user_id, reward_id) WHERE source = 'gift';
+
+-- "Which gifts is this devotee still to open?" — the blurred tiles.
+CREATE INDEX IF NOT EXISTS sadhna_reward_grants_unopened_idx
+    ON sadhna_reward_grants (user_id) WHERE celebrated_at IS NULL;