Initial commit MKD fixes

backend/migrations/create_pr_smm_channels.sql

@@ -0,0 +1,28 @@
+-- PR SMM: каналы и снимки подписчиков
+-- Каналы (Telegram, VK, WhatsApp и др.)
+CREATE TABLE IF NOT EXISTS pr_smm_channels (
+  id                BIGSERIAL PRIMARY KEY,
+  name              TEXT NOT NULL,
+  type              VARCHAR(20) NOT NULL CHECK (type IN ('tg', 'vk', 'wa', 'other')),
+  url               TEXT,
+  sort_order        INT NOT NULL DEFAULT 0,
+  created_at        TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_pr_smm_channels_sort ON pr_smm_channels(sort_order);
+
+-- Снимки количества подписчиков по дате (история фиксаций)
+CREATE TABLE IF NOT EXISTS pr_smm_subscriber_snapshots (
+  id                BIGSERIAL PRIMARY KEY,
+  channel_id        BIGINT NOT NULL REFERENCES pr_smm_channels(id) ON DELETE CASCADE,
+  subscribers_count INT NOT NULL,
+  recorded_at       DATE NOT NULL DEFAULT CURRENT_DATE,
+  note              TEXT,
+  created_at        TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_pr_smm_snapshots_channel ON pr_smm_subscriber_snapshots(channel_id);
+CREATE INDEX IF NOT EXISTS idx_pr_smm_snapshots_recorded ON pr_smm_subscriber_snapshots(recorded_at DESC);
+
+COMMENT ON TABLE pr_smm_channels IS 'SMM-каналы УК: Telegram, VK, WhatsApp и др.';
+COMMENT ON TABLE pr_smm_subscriber_snapshots IS 'Фиксации количества подписчиков по дате для истории';