Add WebManifest, base social metadata, noindex on non-pages; Add /api/items and adapt storing to support it; Improve auth handling and add session verification; Fix #11; Improve editing page with image paste from clipboard and file upload preview; Add footer; Autogenerate config

_util.py

@@ -0,0 +1,11 @@
+def read_textual(filepath:str) -> str:
+    try:
+        with open(filepath, "r", encoding="utf-8") as f:
+            return f.read()
+    except UnicodeDecodeError:
+        with open(filepath, "r") as f:
+            return f.read()
+
+def write_textual(filepath:str, content:str):
+    with open(filepath, "w", encoding="utf-8") as f:
+        return f.write(content)