Add partner SMS gateway via Gama SendQuick and document it.

Expose POST /public/sms/send with API key + domain allowlist for external backends like Balout, wire Meshkee OTP/message sends to Gama, and publish Partner SMS docs on /docs/website.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/redis/redis.service.ts

@@ -21,4 +21,20 @@ export class RedisService {
   async deleteOtp(cellNumber: string): Promise<void> {
     await this.redis.del(`otp:${cellNumber}`);
   }
+
+  /**
+   * Sliding fixed-window counter. Returns true if the call is within `limit`
+   * for the given key over `windowSeconds`.
+   */
+  async incrementWithLimit(
+    key: string,
+    limit: number,
+    windowSeconds: number,
+  ): Promise<boolean> {
+    const count = await this.redis.incr(key);
+    if (count === 1) {
+      await this.redis.expire(key, windowSeconds);
+    }
+    return count <= limit;
+  }
 }