[feat]: support fs Web DAV

[tachibana-shin]

Hi,

Thanks for project

I find that the source code of the server is highly dependent on node:fs it needs 1 real VPS (money) we can replace it with webDAV to be able to deploy this to free serverless services like cloudflare worker or deno deploy

[tachibana-shin]

i can deploy 1 PoC for this or even complete integration but I don't have maintenance time and want this repo maintained.