harden: key remembered site permissions by full origin (closes #402)

allowedSites and deniedSites held the bare hostname, so a grant to
https://dapp.example also authorised http://dapp.example and every port
on that host, and the connection, transaction and signature prompts
named only the hostname. Both lists now store and match the full origin
(scheme://host[:port]), the key the connections approved without
Remember already used. The prompts, the Settings site lists and
AUTISTMASK_REMOVE_SITE use the origin too. Entries saved by hostname
are not migrated (pre-1.0): they match no site.

Model: opus-5-5

docs/README.md

@@ -285,11 +285,13 @@ not appear and may be permanently lost.
 AutistMask injects a standard `window.ethereum` provider (EIP-1193) into web
 pages. When a site requests access to your wallet:
 
-1. A popup appears showing the site's hostname and the address that will be
-   shared.
+1. A popup appears showing the site's origin (its scheme, host and port, for
+   example `https://app.example`) and the address that will be shared.
 2. Click "Allow" to connect or "Deny" to reject.
 3. Optionally check "Remember my choice for this site" to skip the prompt next
-   time.
+   time. The choice applies to that exact origin only: a choice remembered for
+   `https://app.example` does not cover `http://app.example` or another port of
+   the same host, which ask again.
 
 When a connected site requests a transaction, a separate approval popup appears
 showing the transaction details (from, to, value, data, network fee, network and