feat: migrate INWX DNS CLI to interactive Textual TUI

- replace CLI menu with multi-panel Textual interface (sidebar & data table)
- implement asynchronous loading for domains and DNS records via worker threads
- add support for optional 2FA/TOTP auto-unlock and manual TAN modal
- introduce .env configuration fallback for stored credentials
- add modals for creating, editing, and deleting DNS records
- enable inline row editing via mouse double-click and keyboard navigation
- update project documentation in README.md

inwx_api.py

@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""INWX DNS TUI Client
+Author:  Pascal Bouquet <pascal@ptbos.de>
+License: GNU General Public License v3.0 (GPL-3.0)
+Year:    2026
+"""
+
+import os
+import json
+import requests
+from dotenv import load_dotenv
+
+load_dotenv()
+
+API_ENDPOINT = "https://api.domrobot.com/jsonrpc/"
+SESSION_ID = None
+
+def get_stored_credentials():
+    user = os.getenv("INWX_USER", "").strip()
+    pwd = os.getenv("INWX_PASS", "").strip()
+    secret = os.getenv("INWX_2FA_SECRET", "").strip()
+    
+    placeholders = {"", "username", "dein_nutzername", "dein_benutzername", "example_user", "password", "passwort"}
+    if user.lower() in placeholders or pwd.lower() in placeholders:
+        return None, None, secret
+    return user, pwd, secret
+
+def api_call(method, params=None):
+    global SESSION_ID
+    if params is None:
+        params = {}
+
+    headers = {"Content-Type": "application/json"}
+    if SESSION_ID:
+        headers["Cookie"] = f"domrobot={SESSION_ID}"
+
+    payload = {
+        "jsonrpc": "2.0",
+        "method": method,
+        "params": params,
+        "id": 1
+    }
+
+    try:
+        response = requests.post(API_ENDPOINT, headers=headers, data=json.dumps(payload), timeout=12)
+        response.raise_for_status()
+        return response.json()
+    except requests.exceptions.RequestException as e:
+        return {"code": -1, "msg": f"Netzwerkfehler: {e}"}
+
+def login(user, password):
+    global SESSION_ID
+    headers = {"Content-Type": "application/json"}
+    payload = {
+        "jsonrpc": "2.0",
+        "method": "account.login",
+        "params": {"user": user, "pass": password},
+        "id": 1
+    }
+
+    try:
+        response = requests.post(API_ENDPOINT, headers=headers, data=json.dumps(payload), timeout=12)
+        response.raise_for_status()
+        result = response.json()
+
+        if result.get("code") == 1000:
+            if "domrobot" in response.cookies:
+                SESSION_ID = response.cookies["domrobot"]
+            else:
+                return "ERROR", "Kein Session-Cookie von INWX erhalten."
+
+            res_data = result.get("resData", {})
+            tfa_val = res_data.get("tfa")
+
+            # INWX liefert bei inaktivem 2FA None, 0, "0" oder "NONE"
+            if tfa_val in (0, "0", None, False, "", "NONE", "none"):
+                return "SUCCESS", "Login erfolgreich."
+
+            return "NEEDS_2FA", f"2FA erforderlich ({tfa_val})."
+            
+        return "ERROR", result.get("msg", "Zugangsdaten ungültig.")
+    except requests.exceptions.RequestException as e:
+        return "ERROR", str(e)
+
+def unlock_2fa(tan_code):
+    res = api_call("account.unlock", {"tan": str(tan_code).strip()})
+    if res.get("code") == 1000:
+        return True, "2FA erfolgreich entsperrt."
+    return False, res.get("msg", "2FA-Code ungültig.")
+
+def logout():
+    global SESSION_ID
+    if SESSION_ID:
+        api_call("account.logout")
+        SESSION_ID = None
+
+def get_domain_list():
+    res = api_call("nameserver.list")
+    if res.get("code") == 1000:
+        domains_data = res.get("resData", {}).get("domains", [])
+        return True, [d.get("domain") for d in domains_data if "domain" in d]
+    return False, res.get("msg", "Fehler beim Abrufen der Domainliste.")
+
+def get_dns_records(domain):
+    res = api_call("nameserver.info", {"domain": domain})
+    if res.get("code") == 1000:
+        return True, res.get("resData", {}).get("record", [])
+    return False, res.get("msg", "Fehler beim Laden der Records.")
+
+def add_dns_record(domain, name, record_type, content, ttl):
+    params = {
+        "domain": domain,
+        "name": name,
+        "type": record_type,
+        "content": content,
+        "ttl": int(ttl)
+    }
+    res = api_call("nameserver.createRecord", params)
+    return res.get("code") == 1000, res.get("msg", "OK")
+
+def update_dns_record(record_id, content=None, ttl=None):
+    params = {"id": int(record_id)}
+    if content:
+        params["content"] = content
+    if ttl:
+        params["ttl"] = int(ttl)
+    res = api_call("nameserver.updateRecord", params)
+    return res.get("code") == 1000, res.get("msg", "OK")
+
+def delete_dns_record(record_id):
+    res = api_call("nameserver.deleteRecord", {"id": int(record_id)})
+    return res.get("code") == 1000, res.get("msg", "OK")