feat: add workflow studio and postgres support

migrations_pg/20260518000001_usage_logs.sql

@@ -0,0 +1,37 @@
+-- Usage tracking tables migrated from the Node.js backend.
+
+CREATE TABLE IF NOT EXISTS usage_logs (
+    id BIGSERIAL PRIMARY KEY,
+    downstream_key_id BIGINT,
+    model TEXT,
+    prompt_tokens BIGINT DEFAULT 0,
+    completion_tokens BIGINT DEFAULT 0,
+    total_tokens BIGINT DEFAULT 0,
+    cost DOUBLE PRECISION DEFAULT 0.0,
+    created_at TEXT DEFAULT (CURRENT_TIMESTAMP::TEXT),
+    FOREIGN KEY (downstream_key_id) REFERENCES downstream_api_keys(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS usage_logs_downstream_key_created_idx
+    ON usage_logs (downstream_key_id, created_at);
+
+CREATE INDEX IF NOT EXISTS usage_logs_created_idx
+    ON usage_logs (created_at);
+
+CREATE TABLE IF NOT EXISTS usage_daily_snapshots (
+    id BIGSERIAL PRIMARY KEY,
+    local_day TEXT NOT NULL,
+    downstream_key_id BIGINT,
+    request_count BIGINT NOT NULL DEFAULT 0,
+    prompt_tokens BIGINT NOT NULL DEFAULT 0,
+    completion_tokens BIGINT NOT NULL DEFAULT 0,
+    total_tokens BIGINT NOT NULL DEFAULT 0,
+    total_cost DOUBLE PRECISION NOT NULL DEFAULT 0.0,
+    created_at TEXT DEFAULT (CURRENT_TIMESTAMP::TEXT),
+    updated_at TEXT DEFAULT (CURRENT_TIMESTAMP::TEXT),
+    UNIQUE(),
+    FOREIGN KEY (downstream_key_id) REFERENCES downstream_api_keys(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS usage_daily_snapshots_day_idx
+    ON usage_daily_snapshots (local_day);