[feat] Excessive data stored in browser/RAM usage

I noted that webmail is actually using like 800mb-1gb of browser data. Chrome browser may suddenly close on android using webmail...
It happened several times, even if i delete the full cache data every a few days.
Mailbox is quite small with only 1 month of emails.

Please check data/ram usage to keep webmail as light as possible. On desktop PC may work better but on phones with less RAM it could be a problem working.

Thanks

Start by profiling the webmail PWA in Chrome on Android with a small mailbox and one month of emails, measuring browser storage and RAM usage before and after clearing cache. Investigate whether local caching, offline data, or full-text search contributes to the growth. Done means usage is substantially reduced and the webmail no longer causes the browser to close during normal mobile use.

Written by the indexing model from the issue text.