fix(doctor): drop obsolete paru repo check, cover walker + nautilus

The `[moonarch-pkgbuilds]` paru-repo check was a false failure: that
mechanism was retired on 2026-04-20 and the install hook strips the
legacy paru.conf section on upgrade.

Audit of the rest of the doctor surfaced two related gaps — the
user-services loop skipped `walker.service` and `nautilus.service`,
even though moonarch-git ships both and enables them via
graphical-session.target.wants. Added them to the loop and filled in
the missing `wlsunset` in the CLAUDE.md listing.

scripts/moonarch-doctor

@@ -178,7 +178,7 @@ section "User Services"
 if [[ $EUID -eq 0 ]]; then
     warn "Running as root — skipping user service checks"
 else
-    for svc in kanshi wlsunset stasis cliphist-text cliphist-image; do
+    for svc in kanshi wlsunset stasis walker nautilus cliphist-text cliphist-image; do
         check_user_service "$svc"
     done
 fi
@@ -270,13 +270,6 @@ else
     fail "Pacman [moonarch] repo missing from /etc/pacman.conf"
 fi
 
-# Paru PKGBUILD repo
-if grep -q '\[moonarch-pkgbuilds\]' /etc/paru.conf 2>/dev/null; then
-    pass "Paru [moonarch-pkgbuilds] repo configured"
-else
-    fail "Paru [moonarch-pkgbuilds] repo missing from /etc/paru.conf"
-fi
-
 # Default shell
 USER_SHELL=$(getent passwd "$USER" | cut -d: -f7)
 if [[ "$USER_SHELL" == */zsh ]]; then