[Bug]: PWA manifest - use relative path for start URL

[kade-d]

Checklist

• I have updated to the latest available Frigate version.
• I have cleared the cache of my browser.
• I have tried a different browser to see if it is related to my browser.
• I have tried reproducing the issue in incognito mode to rule out problems with any third party extensions or plugins I have installed.

Describe the problem you are having

When frigate is served at a subdirectory like https://server.com/frigate and it is installed as a PWA, launching the PWA opens the base URL https://server.com instead of the subdirectory https://server.com/frigate.

I believe this can be fixed by using a relative path like ./ for the start_url instead of / in the web manifest

Steps to reproduce

1. Host frigate at a subfolder, e.g., https://server.com/frigate
2. Open frigate in iOS at https://server.com/frigate and select "Add to Home Screen" in Safari or Chrome
3. Open the PWA that was installed at the iOS home screen
4. You will be taken to https://server.com instead of https://server.com/frigate

Version

0.14.1-f4f3cfa

In which browser(s) are you experiencing the issue with?

Google Chrome: 128.0.6613.120

Frigate config file

N/A

docker-compose file or Docker CLI command

N/A

Relevant Frigate log output

N/A

Relevant go2rtc log output

N/A

Operating system

Debian

Install method

Docker Compose

Network connection

Wired

Camera make and model

N/A

Screenshots of the Frigate UI's System metrics pages

N/A

Any other information that may be helpful

No response

[NickM-27]

I'll have to double check but I believe doing this caused other issues

[kade-d]

I'm unable to host frigate at a subdomain for reasons out of my control, but I ended up just hosting frigate at a specific port instead of a subdirectory to work around this so not an issue for me anymore