fix: SSH password prompt on auth failure, version from Go backend, visible errors

- ConnectSSH returns NO_CREDENTIALS error when no credential is stored
- Frontend catches auth failures and prompts for username/password
- ConnectSSHWithPassword method for ad-hoc password auth
- Version loaded from Go backend (build-time -ldflags) in settings + unlock screen
- Connection errors shown as alert() instead of silent console.error
- Added UpdateService.CurrentVersion() and WraithApp.GetVersion()

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

frontend/src/components/common/SettingsModal.vue

@@ -335,6 +335,9 @@ onMounted(async () => {
     if (theme) settings.value.terminalTheme = theme;
     if (fontSize) settings.value.fontSize = Number(fontSize);
     if (scrollback) settings.value.scrollbackBuffer = Number(scrollback);
+    // Load version from Go backend
+    const ver = await Call.ByName(`${APP}.GetVersion`) as string;
+    if (ver) currentVersion.value = ver;
   } catch (err) {
     console.error("Failed to load settings:", err);
   }
@@ -360,7 +363,8 @@ watch(() => settings.value.scrollbackBuffer, (val) => {
 // --- Update check state ---
 type UpdateCheckState = "idle" | "checking" | "found" | "up-to-date" | "error";
 const updateCheckState = ref<UpdateCheckState>("idle");
-const currentVersion = ref("0.1.0-dev");
+const APP = "github.com/vstockwell/wraith/internal/app.WraithApp";
+const currentVersion = ref("loading...");
 const latestVersion = ref("");
 
 function open(): void {

frontend/src/layouts/UnlockLayout.vue

@@ -68,7 +68,7 @@
 
       <!-- Version -->
       <p class="text-center text-xs text-[var(--wraith-text-muted)] mt-4">
-        v1.0.0-alpha
+        v{{ appVersion }}
       </p>
     </div>
   </div>
@@ -76,17 +76,24 @@
 
 <script setup lang="ts">
 import { ref, onMounted } from "vue";
+import { Call } from "@wailsio/runtime";
 import { useAppStore } from "@/stores/app.store";
 
+const APP = "github.com/vstockwell/wraith/internal/app.WraithApp";
 const appStore = useAppStore();
 
 const password = ref("");
 const confirmPassword = ref("");
 const submitting = ref(false);
 const passwordInput = ref<HTMLInputElement | null>(null);
+const appVersion = ref("...");
 
-onMounted(() => {
+onMounted(async () => {
   passwordInput.value?.focus();
+  try {
+    const ver = await Call.ByName(`${APP}.GetVersion`) as string;
+    if (ver) appVersion.value = ver;
+  } catch { /* ignore */ }
 });
 
 async function handleSubmit(): Promise<void> {

frontend/src/stores/session.store.ts

@@ -17,6 +17,7 @@ export const useSessionStore = defineStore("session", () => {
   const sessions = ref<Session[]>([]);
   const activeSessionId = ref<string | null>(null);
   const connecting = ref(false);
+  const lastError = ref<string | null>(null);
 
   const activeSession = computed(() =>
     sessions.value.find((s) => s.id === activeSessionId.value) ?? null,
@@ -72,13 +73,38 @@ export const useSessionStore = defineStore("session", () => {
     connecting.value = true;
     try {
       if (conn.protocol === "ssh") {
-        // Call Go backend — resolves credentials, builds auth, returns sessionID
-        const sessionId = await Call.ByName(
-          `${APP}.ConnectSSH`,
-          connectionId,
-          120, // cols (will be resized by xterm.js fit addon)
-          40,  // rows
-        ) as string;
+        let sessionId: string;
+
+        try {
+          // Try with stored credentials first
+          sessionId = await Call.ByName(
+            `${APP}.ConnectSSH`,
+            connectionId,
+            120, // cols (will be resized by xterm.js fit addon)
+            40,  // rows
+          ) as string;
+        } catch (sshErr: any) {
+          const errMsg = typeof sshErr === "string" ? sshErr : sshErr?.message ?? String(sshErr);
+
+          // If no credentials, prompt for username/password
+          if (errMsg.includes("NO_CREDENTIALS") || errMsg.includes("unable to authenticate")) {
+            const username = prompt(`Username for ${conn.hostname}:`, "root");
+            if (!username) throw new Error("Connection cancelled");
+            const password = prompt(`Password for ${username}@${conn.hostname}:`);
+            if (password === null) throw new Error("Connection cancelled");
+
+            sessionId = await Call.ByName(
+              `${APP}.ConnectSSHWithPassword`,
+              connectionId,
+              username,
+              password,
+              120,
+              40,
+            ) as string;
+          } else {
+            throw sshErr;
+          }
+        }
 
         sessions.value.push({
           id: sessionId,
@@ -106,9 +132,12 @@ export const useSessionStore = defineStore("session", () => {
         });
         activeSessionId.value = sessionId;
       }
-    } catch (err) {
-      console.error("Connection failed:", err);
-      // TODO: Show error toast in UI
+    } catch (err: any) {
+      const msg = typeof err === "string" ? err : err?.message ?? String(err);
+      console.error("Connection failed:", msg);
+      lastError.value = msg;
+      // Show error as native alert so it's visible without DevTools
+      alert(`Connection failed: ${msg}`);
     } finally {
       connecting.value = false;
     }
@@ -120,6 +149,7 @@ export const useSessionStore = defineStore("session", () => {
     activeSession,
     sessionCount,
     connecting,
+    lastError,
     activateSession,
     closeSession,
     connect,

internal/app/app.go

@@ -301,15 +301,9 @@ func (a *WraithApp) ConnectSSH(connectionID int64, cols, rows int) (string, erro
 		}
 	}
 
-	// Fallback: keyboard-interactive (prompts for password)
+	// If no stored credentials, return an error telling the frontend to prompt
 	if len(authMethods) == 0 {
-		slog.Info("no stored credentials, SSH will attempt keyboard-interactive auth")
-		authMethods = append(authMethods, gossh.KeyboardInteractive(
-			func(name, instruction string, questions []string, echos []bool) ([]string, error) {
-				// No interactive prompt available yet — return empty
-				return make([]string, len(questions)), nil
-			},
-		))
+		return "", fmt.Errorf("NO_CREDENTIALS: no credentials configured for this connection — assign a credential or use ConnectSSHWithPassword")
 	}
 
 	sessionID, err := a.SSH.Connect(conn.Hostname, conn.Port, username, authMethods, cols, rows)
@@ -337,6 +331,53 @@ func (a *WraithApp) ConnectSSH(connectionID int64, cols, rows int) (string, erro
 	return sessionID, nil
 }
 
+// ConnectSSHWithPassword opens an SSH session using an ad-hoc username/password.
+// Used when no stored credential exists — the frontend prompts and passes creds directly.
+func (a *WraithApp) ConnectSSHWithPassword(connectionID int64, username, password string, cols, rows int) (string, error) {
+	conn, err := a.Connections.GetConnection(connectionID)
+	if err != nil {
+		return "", fmt.Errorf("connection not found: %w", err)
+	}
+
+	authMethods := []gossh.AuthMethod{
+		gossh.Password(password),
+		gossh.KeyboardInteractive(func(name, instruction string, questions []string, echos []bool) ([]string, error) {
+			answers := make([]string, len(questions))
+			for i := range answers {
+				answers[i] = password
+			}
+			return answers, nil
+		}),
+	}
+
+	sessionID, err := a.SSH.Connect(conn.Hostname, conn.Port, username, authMethods, cols, rows)
+	if err != nil {
+		return "", fmt.Errorf("SSH connect failed: %w", err)
+	}
+
+	// Register SFTP client
+	if sess, ok := a.SSH.GetSession(sessionID); ok && sess != nil {
+		sftpClient, err := sftplib.NewClient(sess.Client)
+		if err != nil {
+			slog.Warn("failed to create SFTP client", "error", err)
+		} else {
+			a.SFTP.RegisterClient(sessionID, sftpClient)
+		}
+	}
+
+	if _, err := a.db.Exec("UPDATE connections SET last_connected = CURRENT_TIMESTAMP WHERE id = ?", connectionID); err != nil {
+		slog.Warn("failed to update last_connected", "error", err)
+	}
+
+	slog.Info("SSH session started (ad-hoc password)", "sessionID", sessionID, "host", conn.Hostname, "user", username)
+	return sessionID, nil
+}
+
+// GetVersion returns the build-time version string.
+func (a *WraithApp) GetVersion() string {
+	return a.Updater.CurrentVersion()
+}
+
 // DisconnectSession closes an active SSH session and its SFTP client.
 func (a *WraithApp) DisconnectSession(sessionID string) error {
 	a.SFTP.RemoveClient(sessionID)

internal/updater/service.go

@@ -36,6 +36,11 @@ type UpdateService struct {
 	httpClient     *http.Client
 }
 
+// CurrentVersion returns the build-time version string.
+func (u *UpdateService) CurrentVersion() string {
+	return u.currentVersion
+}
+
 // NewUpdateService creates an UpdateService that compares against the
 // supplied currentVersion (semver without "v" prefix, e.g. "0.2.0").
 func NewUpdateService(currentVersion string) *UpdateService {