refactor: improve maintainability by reducing LOC/reuse

apps/api/src/utils/plans.ts

@@ -1,42 +0,0 @@
-export type Plan = "free" | "pro" | "pro2x" | "pro4x" | "lifetime";
-
-export interface PlanLimits {
-  maxMonitors: number;
-  minIntervalS: number;
-  maxRegions: number;
-}
-
-const PLANS: Record<Plan, PlanLimits> = {
-  free:     { maxMonitors: 10,  minIntervalS: 30, maxRegions: 1 },
-  pro:      { maxMonitors: 200, minIntervalS: 5, maxRegions: 99 },
-  pro2x:    { maxMonitors: 400, minIntervalS: 5, maxRegions: 99 },
-  pro4x:    { maxMonitors: 800, minIntervalS: 5, maxRegions: 99 },
-  lifetime: { maxMonitors: 200, minIntervalS: 5, maxRegions: 99 },
-};
-
-export function getPlanLimits(plan: string): PlanLimits {
-  return PLANS[plan as Plan] || PLANS.free;
-}
-
-// Display helpers
-export const PLAN_LABELS: Record<string, string> = {
-  free: "Free", pro: "Pro", pro2x: "Pro 2x", pro4x: "Pro 4x", lifetime: "Lifetime",
-};
-
-export const PRO_MULTIPLIERS = [
-  { plan: "pro",   label: "1x", monitors: 200, interval: "5s", priceMultiplier: 1 },
-  { plan: "pro2x", label: "2x", monitors: 400, interval: "5s", priceMultiplier: 2 },
-  { plan: "pro4x", label: "4x", monitors: 800, interval: "5s", priceMultiplier: 4 },
-];
-
-export const PRO_MONTHLY_USD = 12;
-export const LIFETIME_USD = 140;
-
-// Tier ranking for plan stacking decisions
-const PLAN_RANK: Record<string, number> = {
-  free: 0, pro: 1, lifetime: 1, pro2x: 2, pro4x: 3,
-};
-
-export function planTier(plan: string): number {
-  return PLAN_RANK[plan] ?? 0;
-}

apps/api/src/utils/rate-limit.ts

@@ -1,21 +0,0 @@
-export function createRateLimiter(windowMs = 60_000, cleanupIntervalMs = 5 * 60_000) {
-  const map = new Map<string, { count: number; resetAt: number }>();
-
-  setInterval(() => {
-    const now = Date.now();
-    for (const [key, entry] of map) {
-      if (now > entry.resetAt) map.delete(key);
-    }
-  }, cleanupIntervalMs);
-
-  return function check(key: string, max: number): boolean {
-    const now = Date.now();
-    const entry = map.get(key);
-    if (!entry || now > entry.resetAt) {
-      map.set(key, { count: 1, resetAt: now + windowMs });
-      return true;
-    }
-    entry.count++;
-    return entry.count <= max;
-  };
-}

apps/api/src/utils/token.ts

@@ -1,9 +0,0 @@
-import { timingSafeEqual } from "crypto";
-
-export function safeTokenCompare(a: string | undefined, b: string | undefined): boolean {
-  if (!a || !b) return false;
-  const bufA = Buffer.from(a);
-  const bufB = Buffer.from(b);
-  if (bufA.length !== bufB.length) return false;
-  return timingSafeEqual(bufA, bufB);
-}