fix: add username field to SSH key credential form — was missing entirely

Root cause of pubkey auth failure: SSH key credentials had no username,
so ConnectSSH defaulted to "root" and the server rejected the key.
The SSH key form in ConnectionEditDialog only had Name, PEM, Passphrase.
Added Username field between Name and PEM.

Delete your existing SSH key credentials and re-create them with the
correct username.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/connections/ConnectionEditDialog.vue

@@ -259,6 +259,15 @@
                     class="w-full px-3 py-2 text-sm rounded bg-[#161b22] border border-[#30363d] text-[var(--wraith-text-primary)] placeholder-[var(--wraith-text-muted)] outline-none focus:border-[var(--wraith-accent-blue)] transition-colors"
                   />
                 </div>
+                <div>
+                  <label class="block text-xs text-[var(--wraith-text-secondary)] mb-1">Username</label>
+                  <input
+                    v-model="newCred.username"
+                    type="text"
+                    placeholder="e.g. vstockwell"
+                    class="w-full px-3 py-2 text-sm rounded bg-[#161b22] border border-[#30363d] text-[var(--wraith-text-primary)] placeholder-[var(--wraith-text-muted)] outline-none focus:border-[var(--wraith-accent-blue)] transition-colors"
+                  />
+                </div>
                 <div>
                   <label class="block text-xs text-[var(--wraith-text-secondary)] mb-1">Private Key (PEM)</label>
                   <textarea

internal/app/app.go

@@ -314,6 +314,8 @@ func (a *WraithApp) ConnectSSH(connectionID int64, cols, rows int) (string, erro
 		return "", fmt.Errorf("NO_CREDENTIALS: no credentials configured for this connection — assign a credential or use ConnectSSHWithPassword")
 	}
 
+	slog.Info("SSH auth configured", "username", username, "authMethods", len(authMethods))
+
 	sessionID, err := a.SSH.Connect(conn.Hostname, conn.Port, username, authMethods, cols, rows)
 	if err != nil {
 		return "", fmt.Errorf("SSH connect failed: %w", err)