Allow SCP seed upload with PSK auth

[chrlns]

Using password authentication for SSH is widely considered a security risk. Therefor it would be very helpful if the SCP upload could work with PSK as well. Currently it is required to provide username and password for SCP seed upload.

If one uses a non-empty password for a connection that is host-configured "publickey" the SCP upload failes:

SaveSeedList: Seed upload failed (IO error): SCP: File uploading failed: Auth fail for methods 'publickey'

Publickey is tried here but something failes. I changed net/yacy/peers/operation/yacySeedUploadScp.java to ignore the password but this doesn't help:

I 2025/12/30 10:08:21 NETWORK * SaveSeedList: Seed upload failed (IO error): SCP: File uploading failed: Auth fail for methods 'publickey' java.lang.Exception: SCP: File uploading failed: Auth fail for methods 'publickey' at net.yacy.peers.operation.sshc.put(yacySeedUploadScp.java:197) at net.yacy.peers.operation.yacySeedUploadScp.uploadSeedFile(yacySeedUploadScp.java:83) at net.yacy.peers.SeedDB.uploadSeedList(SeedDB.java:868) at net.yacy.peers.Network.saveSeedList(Network.java:678) at net.yacy.htroot.SettingsAck_p.respond(SettingsAck_p.java:389) at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:104) at java.base/java.lang.reflect.Method.invoke(Method.java:565) at net.yacy.http.servlets.YaCyDefaultServlet.invokeServlet(YaCyDefaultServlet.java:761) at net.yacy.http.servlets.YaCyDefaultServlet.handleTemplate(YaCyDefaultServlet.java:957) at net.yacy.http.servlets.YaCyDefaultServlet.doGet(YaCyDefaultServlet.java:308) at net.yacy.http.servlets.YaCyDefaultServlet.doPost(YaCyDefaultServlet.java:377) at javax.servlet.http.HttpServlet.service(HttpServlet.java:665) at javax.servlet.http.HttpServlet.service(HttpServlet.java:750) at [..]