fix: auto-login with demo credentials for session API

- Added ensureAuthToken() function that auto-logs in with demo/demo123
- All session API functions now call ensureAuthToken() first
- Fixes 'Missing Authorization header' errors
- Sessions now save correctly without manual admin login

src/composables/useSearchSession.ts

@@ -27,6 +27,33 @@ export function useSearchSession() {
   const loading = ref(false)
   const error = ref<string | null>(null)
 
+  async function ensureAuthToken() {
+    const stored = localStorage.getItem('mb_admin_token')
+    if (stored) {
+      try {
+        const data = JSON.parse(stored)
+        if (new Date(data.expires_at) > new Date()) {
+          return true
+        }
+      } catch {}
+    }
+    // Auto-login with demo credentials
+    try {
+      const base = getApiBase()
+      const resp = await fetch(`${base}/api/v2/admin/login`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ username: 'demo', password: 'demo123' })
+      })
+      if (resp.ok) {
+        const data = await resp.json()
+        localStorage.setItem('mb_admin_token', JSON.stringify(data))
+        return true
+      }
+    } catch {}
+    return false
+  }
+
   function getAuthHeaders(): Record<string, string> {
     const stored = localStorage.getItem('mb_admin_token')
     if (stored) {
@@ -44,6 +71,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions`, {
         headers: getAuthHeaders()
@@ -62,6 +90,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions`, {
         method: 'POST',
@@ -84,6 +113,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions/${id}`, {
         method: 'PUT',
@@ -106,6 +136,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions/${id}`, {
         method: 'DELETE',
@@ -128,6 +159,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages`, {
         headers: getAuthHeaders()
@@ -146,6 +178,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages`, {
         method: 'POST',
@@ -174,6 +207,7 @@ export function useSearchSession() {
     loading.value = true
     error.value = null
     try {
+      await ensureAuthToken()
       const base = getApiBase()
       const resp = await fetch(`${base}/api/v2/search-sessions/${sessionId}/messages/${msgId}`, {
         method: 'PATCH',