Fix File Manager rename not updating displayed name (#460)

The rename endpoint updated `filename` but not `file_metadata.print_name`,
which the UI uses as the primary display name. Since print_name is extracted
from the 3MF at upload, it always took precedence over the renamed filename.

Now also updates print_name in file metadata when present.

CHANGELOG.md

@@ -6,6 +6,7 @@ All notable changes to Bambuddy will be documented in this file.
 
 ### Fixed
 - **Developer Mode Detection Always Reports Null** — The MQTT `fun` field is an integer in the JSON payload, but the parser used `int(value, 16)` which requires a string argument. This raised `TypeError` on every message, silently caught by the exception handler, so `developer_mode` was never set. Now handles both integer and hex string formats.
+- **File Manager Rename Doesn't Update Displayed Name** ([#460](https://github.com/maziggy/bambuddy/issues/460)) — Renaming a file in the File Manager updated the `filename` field but not `file_metadata.print_name`, which the UI uses as the primary display name. Since `print_name` is extracted from inside the 3MF at upload time, it always took precedence over the renamed `filename`. The rename endpoint now also updates `print_name` in the file metadata when present.
 
 ## [0.2.1b2] - 2026-02-21
 

backend/app/api/routes/library.py

@@ -1935,6 +1935,9 @@ async def update_file(
         if "/" in data.filename or "\\" in data.filename:
             raise HTTPException(status_code=400, detail="Filename cannot contain path separators")
         file.filename = data.filename
+        # Also update print_name in file_metadata so the display name matches
+        if file.file_metadata and "print_name" in file.file_metadata:
+            file.file_metadata = {**file.file_metadata, "print_name": data.filename}
 
     if data.folder_id is not None:
         if data.folder_id == 0: