fix(inbounds): refuse 2022-blake3-chacha20-poly1305 on shadowsocks inbounds

xray-core builds a Shadowsocks-2022 inbound with users only for the AES
methods: the multi-user identity header is AES-only, so the config
builder and the multi-user server both reject chacha20. Every panel
inbound carries clients, so picking 2022-blake3-chacha20-poly1305 in the
inbound form kept the whole core from starting; its links also failed
on the client with "multi-key is not supported".

The inbound form no longer offers the method and AddInbound/UpdateInbound
reject it. Startup moves stored inbounds to 2022-blake3-aes-256-gcm,
which takes the same 32-byte keys, so every stored key stays valid.
Outbounds keep the method, since a single-key outbound to such a server
works. The share-link generator drops the single-user branch that only
this method reached.

internal/xray/shadowsocks2022.go

@@ -18,3 +18,10 @@ func ValidShadowsocks2022Key(method, key string) bool {
 	_, err := shadowsocks_2022.ParseKey(key, Shadowsocks2022KeyBytes(method))
 	return err == nil
 }
+
+// Shadowsocks2022NoMultiUser reports a 2022 method xray-core refuses on an
+// inbound with users: the multi-user identity header is AES-only.
+func Shadowsocks2022NoMultiUser(method string) bool {
+	cipher, err := shadowsocks_2022.GetCipherMethod(method)
+	return err == nil && cipher.IsChaCha
+}