fix: uploaded files with no extension become permanently unresolvable (#1275)

* fix: accept extensionless upload ids so files like Dockerfile resolve

* test: upload id validation accepts extensionless ids

src/upload_handler.py

@@ -31,7 +31,11 @@ import logging
 
 logger = logging.getLogger(__name__)
 
-UPLOAD_ID_RE = re.compile(r"^[0-9a-fA-F]{32}\.[A-Za-z0-9]+$")
+# The extension is optional: save_upload builds the id as `{uuid.hex}{ext}`,
+# and a file with no extension (Dockerfile, README, ...) yields a bare 32-hex
+# id. Requiring `.ext` made those ids fail validation, so the stored file
+# could never be resolved or downloaded again.
+UPLOAD_ID_RE = re.compile(r"^[0-9a-fA-F]{32}(?:\.[A-Za-z0-9]+)?$")
 
 
 def is_valid_upload_id(upload_id: str) -> bool: