A failed Wi-Fi connect leaves the wrong passphrase in iwd with AutoConnect=true

[eliasbakken]

Found testing v1.1.0-RC8-2-g23a2bb6 on A8 s/n 0498.

What happens

After a Connect attempt with a wrong passphrase, wifi-connect restores the hotspot, but the profile it wrote stays behind:

/var/lib/iwd/Kraakeslottet.psk
[Settings]
AutoConnect=true
[Security]
Passphrase=<the wrong one>

iwd then keeps trying it by itself while the script waits for DHCP (journalctl -u iwd):

event: state, old: autoconnect_full, new: connecting (auto)
Received Deauthentication event, reason: 2, from_ap: true
event: state, old: connecting (auto), new: disconnected
event: state, old: disconnected, new: autoconnect_full
... repeats

Why it matters

• WiFi credentials silently lost: options panel clobbers them, and they are saved even when the connection fails #124 moved the options write to after a successful connect so a bad passphrase is not kept. The iwd profile is written before the attempt and never removed, so the bad passphrase is kept anyway, one layer down, with autoconnect on.
• If the board already had a working profile for that SSID, a mistyped retry overwrites it. The server comment "previous working credentials survive a failed attempt" holds for options.cfg but not for iwd.

Suggested direction

On failure, restore_hotspot should restore whatever profile was there before (or delete the new one). Alternatively, write the profile somewhere temporary and move it into place only on success.

[eliasbakken]

Fixed in #158 (merged as d611c55), commit 6400dfc. The profile is written before the attempt with AutoConnect=true and was never removed, so a wrong passphrase stayed in /var/lib/iwd and iwd retried it by itself, and a mistyped retry overwrote a profile that worked. The previous profile is now kept aside and put back on failure, or the new one forgotten if there was none.

Checked on A8 0498: after a failed attempt /var/lib/iwd holds only ap and hotspot again, and with a previous profile present its passphrase is restored.