Make Nextcloud user and password mandatory for all sites

- NC User and NC Pass are now required fields when adding a site
- Auto-provision Nextcloud user on site creation
- Client-side validation enforces all fields in both Add and Edit forms
- Updated placeholder text to reflect required status
- Sites without NC creds now show Not set badge instead of Global

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app.py

@@ -981,14 +981,15 @@ def admin_dashboard():
 def admin_add_site():
     """Add a new site to sites.conf.
 
-    JSON body: {site, pin, nc_user?, nc_pass?}
+    JSON body: {site, pin, nc_user, nc_pass}
     Site must be exactly 4 digits and must not already exist.
+    NC User and NC Pass are required.
     """
     data = request.get_json(force=True)
     site = data.get("site", "").strip()
     pin = data.get("pin", "").strip()
-    nc_user = data.get("nc_user", "").strip() or None
-    nc_pass = data.get("nc_pass", "").strip() or None
+    nc_user = data.get("nc_user", "").strip()
+    nc_pass = data.get("nc_pass", "").strip()
 
     if not re.fullmatch(r"\d{4}", site):
         return jsonify({"ok": False, "error": "Site must be exactly 4 digits"}), 400
@@ -996,6 +997,12 @@ def admin_add_site():
     if not pin:
         return jsonify({"ok": False, "error": "PIN is required"}), 400
 
+    if not nc_user:
+        return jsonify({"ok": False, "error": "NC User is required"}), 400
+
+    if not nc_pass:
+        return jsonify({"ok": False, "error": "NC Pass is required"}), 400
+
     # Reject characters that would corrupt sites.conf (colon is the
     # field delimiter, newlines would inject extra lines)
     for field_name, value in [("PIN", pin), ("NC User", nc_user), ("NC Pass", nc_pass)]:
@@ -1011,7 +1018,18 @@ def admin_add_site():
 
     sites[site] = {"pin": pin, "nc_user": nc_user, "nc_pass": nc_pass}
     save_sites(sites)
-    return jsonify({"ok": True})
+
+    # Auto-provision the Nextcloud user
+    nc_msg = None
+    if all([NC_URL, NC_USER, NC_PASS]):
+        if nc_user_exists(nc_user):
+            nc_msg = f"NC user '{nc_user}' already exists"
+        elif nc_create_user(nc_user, nc_pass):
+            nc_msg = f"NC user '{nc_user}' created"
+        else:
+            nc_msg = f"Site saved, but failed to create NC user '{nc_user}'"
+
+    return jsonify({"ok": True, "nc_msg": nc_msg})
 
 
 @app.route("/admin/api/sites/<site_id>", methods=["PUT"])