feat: implement reasoning_tokens tracking and enhanced usage logging

src/database/mod.rs

@@ -64,6 +64,7 @@ pub async fn run_migrations(pool: &DbPool) -> Result<()> {
             model TEXT,
             prompt_tokens INTEGER,
             completion_tokens INTEGER,
+            reasoning_tokens INTEGER DEFAULT 0,
             total_tokens INTEGER,
             cost REAL,
             has_images BOOLEAN DEFAULT FALSE,
@@ -172,6 +173,9 @@ pub async fn run_migrations(pool: &DbPool) -> Result<()> {
     let _ = sqlx::query("ALTER TABLE llm_requests ADD COLUMN cache_write_tokens INTEGER DEFAULT 0")
         .execute(pool)
         .await;
+    let _ = sqlx::query("ALTER TABLE llm_requests ADD COLUMN reasoning_tokens INTEGER DEFAULT 0")
+        .execute(pool)
+        .await;
 
     // Add billing_mode column if it doesn't exist (migration for existing DBs)
     let _ = sqlx::query("ALTER TABLE provider_configs ADD COLUMN billing_mode TEXT")