migrate from gotify to ntfy with image attachment support

- Replace GotifyNotifier with NtfyNotifier for push notifications
- Add support for sending email image attachments to ntfy
- Add NTFY_URL, NTFY_TOKEN, NTFY_TOPIC environment variables
- Add get_mailpit_image() and get_mailpit_image_thumb() helpers
- Sanitize message content for HTTP headers (remove newlines)
- Remove all gotify references

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/utils/ntfy_api.py

@@ -0,0 +1,81 @@
+import requests
+
+
+class NtfyNotifier:
+
+    def __init__(self, server_url: str, api_token: str, topic: str):
+        self.base_url = server_url.rstrip('/')
+        self.token = api_token
+        self.topic = topic
+
+    def send(self, title: str = "Test", message: str = "testing msg", priority: int = 5) -> bool:
+        """
+        Send a text message to Ntfy.
+
+        Args:
+            title (str): Title of the notification.
+            message (str): Body of the notification.
+            priority (int, optional): Message priority (1-5). Defaults to 5.
+
+        Returns:
+            bool: True if the message was sent successfully, False otherwise.
+        """
+        if not self.base_url or not self.token or not self.topic:
+            print("[!] Missing NTFY_URL, NTFY_TOKEN, or NTFY_TOPIC")
+            return False
+
+        url = f"{self.base_url}/{self.topic}"
+
+        headers = {
+            "Authorization": f"Bearer {self.token}",
+            "Title": title,
+            "Priority": str(priority),
+        }
+
+        try:
+            response = requests.post(url, headers=headers, data=message, timeout=10)
+            response.raise_for_status()
+            return True
+        except requests.RequestException as e:
+            print(f"[!] Failed to send Ntfy message: {e}")
+            return False
+
+    def send_with_image(self, title: str, message: str, image_data: bytes,
+                        filename: str = "image.jpg", priority: int = 5) -> bool:
+        """
+        Send a notification with an attached image to Ntfy.
+
+        Args:
+            title (str): Title of the notification.
+            message (str): Body of the notification.
+            image_data (bytes): Binary image data to attach.
+            filename (str): Filename for the attachment. Defaults to "image.jpg".
+            priority (int, optional): Message priority (1-5). Defaults to 5.
+
+        Returns:
+            bool: True if the message was sent successfully, False otherwise.
+        """
+        if not self.base_url or not self.token or not self.topic:
+            print("[!] Missing NTFY_URL, NTFY_TOKEN, or NTFY_TOPIC")
+            return False
+
+        url = f"{self.base_url}/{self.topic}"
+
+        # Sanitize message for HTTP header (no newlines/carriage returns allowed)
+        safe_message = message.replace('\r', ' ').replace('\n', ' ').strip()
+
+        headers = {
+            "Authorization": f"Bearer {self.token}",
+            "Title": title,
+            "Priority": str(priority),
+            "Filename": filename,
+            "Message": safe_message,
+        }
+
+        try:
+            response = requests.put(url, headers=headers, data=image_data, timeout=10)
+            response.raise_for_status()
+            return True
+        except requests.RequestException as e:
+            print(f"[!] Failed to send Ntfy message with image: {e}")
+            return False