Some updates to Lighthouse book (#6995)

* #6447


  - Move some deprecated pages to a new section under `Archived`

- Remove fallback log in mev as the log will not be present after VC using `/eth/v3/validator/blocks` endpoint by default
- Add warning against using Btrfs file system (thank you @ChosunOne for the report)
- Add data shared by @mcdee  on tree states API queries time
- Rename partial withdrawals to validator sweep to differentiate it from the upcoming execution layer partial withdrawals
- Update NAT API response
- Update docs on IPv6

- Rename .md files to follow a standard prefix section name, e.g., installation_*.md, advanced_*.md
- Standardise .md files using underscore `_` instead of hyphen `-` to be consistent with other files naming conventions.

book/src/ui_authentication.md

@@ -0,0 +1,13 @@
+# Authentication
+
+## Siren Session
+
+For enhanced security, Siren will require users to authenticate with their session password to access the dashboard. This is crucial because Siren now includes features that can permanently alter the status of the user's validators. The session password must be set during the [configuration](./ui_configuration.md) process before running the Docker or local build, either in an `.env` file or via Docker flags.
+
+![exit](imgs/ui-session.png)
+
+## Protected Actions
+
+Prior to executing any sensitive validator action, Siren will request authentication of the session password. If you wish to update your password please refer to the Siren [configuration process](./ui_configuration.md).
+
+![exit](imgs/ui-auth.png)