Fix infinite save retry loop and method check bugs

[makermelissa-piclaw]

Summary

Fixes #460 — Cannot Save code.py Edits on Adafruit Qualia ESP32-S3

The Problem

When saving a file fails (e.g., due to a connection issue or board being busy), saveFileContents() catches the error and retries via setTimeout(saveFileContents, 2000) with no retry limit. This creates an infinite loop that:

• Retries the save every 2 seconds forever
• Causes the editor to appear to "reload" continuously (as reported in Cannot Save code.py Edits on Adafruit Qualia ESP32-S3 for TTL RGB-666 Displays #460)
• Never shows the user an error message
• Continues even after disconnecting or switching to a different board

Changes

js/script.js:

• Add a retry counter with a max of 3 attempts for saveFileContents()
• Show a clear error message to the user when retries are exhausted
• Reset retry counter on successful save
• Clear the retry timeout and reset counter on disconnect (prevents phantom retries after switching boards)
• Fix missing closing quote in save failure message template literal

js/common/web-file-transfer.js:

• Fix _isMethodAllowed(): method.toUpperCase was missing (), passing the function reference instead of calling it — so the method check always returned false
• Add missing await on _isMethodAllowed() call in _fetch() so the permission check result is actually evaluated (previously the unawaited Promise was always truthy, making the check dead code)

Testing

• Build passes with vite build
• The Qualia-specific save failure likely has a firmware component too (display DMA contention during web server PUT), but this fix prevents the editor from looping forever regardless of the cause

[makermelissa]

Looks good and I see there were some bugs you caught that had been previously missed.