Update image fees to 50 MB free per day (#798)

Almost every stacker was below 50 MB per day (except one stacker at one day).

Since storage is cheap, we can allow 50 MB per day for free; especially since UX around image fees suck.

prisma/migrations/20240209001227_update_image_fees/migration.sql

@@ -0,0 +1,39 @@
+-- update image fees from free 10 MB per stacker per 24 hours to
+-- free 50 MB per stacker per 24 hours
+CREATE OR REPLACE FUNCTION image_fees_info(user_id INTEGER, upload_ids INTEGER[])
+RETURNS TABLE (
+    "bytes24h" INTEGER,
+    "bytesUnpaid" INTEGER,
+    "nUnpaid" INTEGER,
+    "imageFeeMsats" BIGINT
+)
+LANGUAGE plpgsql
+AS $$
+BEGIN
+    RETURN QUERY SELECT
+        uploadinfo.*,
+        CASE
+            -- anons always pay 100 sats per image
+            WHEN user_id = 27 THEN 100000::BIGINT
+            ELSE CASE
+            -- 50 MB are free per stacker and 24 hours
+            WHEN uploadinfo."bytes24h" + uploadinfo."bytesUnpaid" <= 50 * 1024 * 1024 THEN 0::BIGINT
+            WHEN uploadinfo."bytes24h" + uploadinfo."bytesUnpaid" <= 75 * 1024 * 1024 THEN 10000::BIGINT
+            WHEN uploadinfo."bytes24h" + uploadinfo."bytesUnpaid" <= 100 * 1024 * 1024 THEN 100000::BIGINT
+            ELSE 1000000::BIGINT
+        END
+    END AS "imageFeeMsats"
+    FROM (
+        SELECT
+            -- how much bytes did stacker upload in last 24 hours?
+            COALESCE(SUM(size) FILTER(WHERE paid = 't' AND created_at >= NOW() - interval '24 hours'), 0)::INTEGER AS "bytes24h",
+            -- how much unpaid bytes do they want to upload now?
+            COALESCE(SUM(size) FILTER(WHERE paid = 'f' AND id = ANY(upload_ids)), 0)::INTEGER AS "bytesUnpaid",
+            -- how many unpaid images do they want to upload now?
+            COALESCE(COUNT(id) FILTER(WHERE paid = 'f' AND id = ANY(upload_ids)), 0)::INTEGER AS "nUnpaid"
+        FROM "Upload"
+        WHERE "Upload"."userId" = user_id
+    ) uploadinfo;
+    RETURN;
+END;
+$$;