Ensure app reloads without using cache

[cgjgh]

Description

After changes made in this PR #1455, this ensures app still reloads without cache to prevent issues like ones mentioned here: #817, fixed by adding more fine-grained error filtering to prevent errors that should trigger a redirect to auth, to instead result in opening fallback app.

Related Issue(s)

Checklist

• [x] I have read the contribution guidelines
• [ ] Suitable unit/system level tests have been added and they pass
• [ ] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Includes a DB migration? -> add the area:migration label

[cgjgh]

@joepavitt This is ready for review when it fits your busy schedule.