linter fixes, env fixes

app/api/habits/route.ts

@@ -7,11 +7,11 @@ async function getUserFromToken() {
   const token = await getTokenCookie();
   if (!token) return null;
 
-  const [user] = await db.select().from(users).where(eq(users.token, token));
-  return user;
+  const userRows = await db.select().from(users).where(eq(users.token, token));
+  return userRows.length > 0 ? userRows[0] : null;
 }
 
-export async function GET(request: NextRequest) {
+export async function GET() {
   try {
     const user = await getUserFromToken();
     if (!user) {
@@ -83,7 +83,13 @@ export async function POST(request: NextRequest) {
       return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
     }
 
-    const body = await request.json();
+    const body = (await request.json()) as {
+      name: string;
+      type: string;
+      targetFrequency?: { value: number; period: 'day' | 'week' | 'month' };
+      color?: string;
+      icon?: string;
+    };
     const { name, type, targetFrequency, color, icon } = body;
 
     if (!name || !type) {
@@ -95,18 +101,33 @@ export async function POST(request: NextRequest) {
       );
     }
 
-    const [newHabit] = await db
+    // Validate type is one of the allowed enum values
+    if (!['positive', 'neutral', 'negative'].includes(type)) {
+      return NextResponse.json(
+        {
+          error: 'Type must be one of: positive, neutral, negative',
+        },
+        { status: 400 },
+      );
+    }
+
+    const newHabitRows = await db
       .insert(habits)
       .values({
         userId: user.id,
         name,
-        type,
+        type: type as 'positive' | 'neutral' | 'negative',
         targetFrequency,
         color,
         icon,
       })
       .returning();
 
+    if (newHabitRows.length === 0) {
+      throw new Error('Failed to create habit');
+    }
+
+    const newHabit = newHabitRows[0];
     return NextResponse.json({ habit: newHabit });
   } catch (error) {
     console.error('Create habit error:', error);