Now supports running under a sub path

Just set the SPOOLMAN_BASE_PATH environment variable and it should work.

Resolves #95

spoolman/client.py

@@ -2,24 +2,37 @@
 
 # ruff: noqa: PTH118
 
+import logging
 import os
+from pathlib import Path
 from typing import Union
 
 from fastapi.staticfiles import StaticFiles
 
+logger = logging.getLogger(__name__)
+
 
 class SinglePageApplication(StaticFiles):
     """Serve a single page application."""
 
-    def __init__(self, directory: str) -> None:
+    def __init__(self, directory: str, base_path: str) -> None:
         """Construct."""
         super().__init__(directory=directory, packages=None, html=True, check_dir=True)
+        self.base_path = base_path.removeprefix("/")
 
     def lookup_path(self, path: str) -> tuple[str, Union[os.stat_result, None]]:
         """Return index.html if the requested file cannot be found."""
+        path = path.removeprefix(self.base_path).removeprefix("/")
+
         full_path, stat_result = super().lookup_path(path)
 
         if stat_result is None:
+            ext = Path(path).suffix
+            # Check if user is looking for some specific non-document file
+            if len(ext) > 1 and ext != ".html":
+                # If so, return 404
+                return ("", None)
+            # Otherwise, they did look for a document, lead them to index.html
             return super().lookup_path("index.html")
 
         return (full_path, stat_result)