Fix API URL: only auto-append /api for bare hostnames

Use urllib.parse to check if the URL has a path component. Only append
/api when the path is empty (e.g. https://silo.kindred.internal).
URLs that already include a path (e.g. http://localhost:8080/api) are
left unchanged. Restore localhost placeholder as the default.

pkg/freecad/silo_commands.py

@@ -29,9 +29,14 @@ def _get_api_url() -> str:
     if not url:
         url = os.environ.get("SILO_API_URL", "http://localhost:8080/api")
     url = url.rstrip("/")
-    # Auto-append /api if the user provided just the base hostname
-    if url and not url.endswith("/api"):
-        url = url + "/api"
+    # Auto-append /api when the user provides just a bare origin with no path,
+    # e.g. "https://silo.kindred.internal" -> "https://silo.kindred.internal/api"
+    # but leave URLs that already have a path alone,
+    # e.g. "http://localhost:8080/api" stays as-is.
+    if url:
+        parsed = urllib.parse.urlparse(url)
+        if not parsed.path or parsed.path == "/":
+            url = url + "/api"
     return url
 
 
@@ -1852,7 +1857,7 @@ class Silo_Settings:
         layout.addWidget(url_label)
 
         url_input = QtGui.QLineEdit()
-        url_input.setPlaceholderText("https://silo.kindred.internal")
+        url_input.setPlaceholderText("http://localhost:8080/api")
         current_url = param.GetString("ApiUrl", "")
         if current_url:
             url_input.setText(current_url)
@@ -1863,9 +1868,9 @@ class Silo_Settings:
         layout.addWidget(url_input)
 
         url_hint = QtGui.QLabel(
-            "Enter the server hostname (e.g. https://silo.kindred.internal). "
-            "The /api path is appended automatically. "
-            "Leave empty to use SILO_API_URL environment variable."
+            "Full URL with path (e.g. http://localhost:8080/api) or just the "
+            "hostname (e.g. https://silo.kindred.internal) and /api is "
+            "appended automatically. Leave empty for SILO_API_URL env var."
         )
         url_hint.setWordWrap(True)
         url_hint.setStyleSheet("color: #888; font-size: 11px;")