Download button gating, format defaults fix, layout/UX polish

Download button:
- Disabled until URL analysis confirms downloadable content
- Shows error message for invalid URLs or pages with no media
- analyzeError state resets when URL is cleared or changed

Admin format defaults fix:
- AdminPanel now reloads configStore after saving settings
- Previously the main page kept stale config until full page refresh
- Config store import added to AdminPanel

Re-download same URL:
- Added overwrites: true to yt-dlp opts so re-downloading the
  same URL with different format options works correctly
- Previously yt-dlp would skip if intermediate file existed

UI polish:
- Clear button fixed-width (min-width: 70px) — no shift between
  'Clear' and 'Sure?' states
- Action buttons uniform sizing (inline-flex, min-width/height,
  box-sizing: border-box) — download/copy/clear all same size
- Footer no longer pushes below viewport — App.vue uses flex
  column layout, AppLayout uses flex:1 instead of min-height:100vh
- Page only scrolls when content exceeds viewport

backend/app/services/download.py

@@ -159,6 +159,7 @@ class DownloadService:
             "no_warnings": True,
             "noprogress": True,
             "noplaylist": True,  # Individual jobs — don't re-expand playlists
+            "overwrites": True,  # Allow re-downloading same URL with different format
         }
         if job_create.format_id:
             opts["format"] = job_create.format_id

frontend/src/App.vue

@@ -22,7 +22,17 @@ onMounted(async () => {
 </script>
 
 <template>
+  <div class="app-root">
     <AppHeader />
     <router-view />
     <AppFooter />
+  </div>
 </template>
+
+<style>
+.app-root {
+  display: flex;
+  flex-direction: column;
+  min-height: 100vh;
+}
+</style>

frontend/src/components/AdminPanel.vue

@@ -2,10 +2,12 @@
 import { onMounted, ref } from 'vue'
 import { useRouter } from 'vue-router'
 import { useAdminStore } from '@/stores/admin'
+import { useConfigStore } from '@/stores/config'
 import { api } from '@/api/client'
 import AdminLogin from './AdminLogin.vue'
 
 const store = useAdminStore()
+const configStore = useConfigStore()
 const router = useRouter()
 const activeTab = ref<'sessions' | 'storage' | 'purge' | 'settings'>('sessions')
 
@@ -52,6 +54,8 @@ async function saveSettings() {
     default_audio_format: defaultAudioFormat.value,
   })
   if (ok) {
+    // Reload public config so main page picks up new defaults
+    await configStore.loadConfig()
     settingsSaved.value = true
     setTimeout(() => { settingsSaved.value = false }, 3000)
   }

frontend/src/components/AppLayout.vue

@@ -52,7 +52,7 @@ const activeTab = ref<MobileTab>('submit')
 .app-layout {
   display: flex;
   flex-direction: column;
-  min-height: calc(100vh - var(--header-height));
+  flex: 1;
 }
 
 .layout-main {

frontend/src/components/DownloadQueue.vue

@@ -195,6 +195,7 @@ function handleClear(): void {
 
 .btn-clear {
   min-height: 36px;
+  min-width: 70px;
   font-size: var(--font-size-sm);
   padding: var(--space-xs) var(--space-md);
   background: var(--color-surface);

frontend/src/components/DownloadTable.vue

@@ -441,11 +441,13 @@ async function clearJob(jobId: string): Promise<void> {
 }
 
 .action-btn {
-  display: flex;
+  display: inline-flex;
   align-items: center;
   justify-content: center;
   width: 30px;
   height: 30px;
+  min-width: 30px;
+  min-height: 30px;
   padding: 0;
   background: transparent;
   border: 1px solid var(--color-border);
@@ -454,6 +456,8 @@ async function clearJob(jobId: string): Promise<void> {
   cursor: pointer;
   transition: all 0.15s ease;
   text-decoration: none;
+  box-sizing: border-box;
+  line-height: 1;
 }
 
 .action-btn:hover {

frontend/src/components/UrlInput.vue

@@ -22,6 +22,7 @@ const audioLocked = ref(false)  // true when source is audio-only
 // Unified loading state for URL check + format extraction
 const isAnalyzing = ref(false)
 const analyzePhase = ref<string>('')
+const analyzeError = ref<string | null>(null)
 const phaseMessages = [
   'Peeking at the URL…',
   'Interrogating the server…',
@@ -95,6 +96,7 @@ watch(url, (newUrl) => {
     formats.value = []
     selectedFormatId.value = null
     extractError.value = null
+    analyzeError.value = null
     audioLocked.value = false
     showOptions.value = false
     selectedEntries.value = new Set()
@@ -104,6 +106,7 @@ watch(url, (newUrl) => {
     formats.value = []
     selectedFormatId.value = null
     extractError.value = null
+    analyzeError.value = null
     audioLocked.value = false
     selectedEntries.value = new Set()
   }
@@ -115,6 +118,11 @@ const selectedEntries = ref<Set<number>>(new Set())
 /** Whether formats have been fetched for the current URL. */
 const formatsReady = computed(() => formats.value.length > 0)
 
+/** URL has been analyzed and content was found. */
+const urlReady = computed(() =>
+  !!urlInfo.value && urlInfo.value.type !== 'unknown'
+)
+
 async function extractFormats(): Promise<void> {
   const trimmed = url.value.trim()
   if (!trimmed) return
@@ -180,9 +188,16 @@ function handlePaste(): void {
   setTimeout(async () => {
     if (url.value.trim()) {
       isAnalyzing.value = true
+      analyzeError.value = null
       startAnalyzePhase()
       try {
         await Promise.all([extractFormats(), fetchUrlInfo()])
+        // Check if URL yielded anything useful
+        if (urlInfo.value?.type === 'unknown') {
+          analyzeError.value = 'No downloadable media found at this URL.'
+        } else if (!urlInfo.value && !extractError.value) {
+          analyzeError.value = 'Could not reach this URL. Check the address and try again.'
+        }
       } finally {
         isAnalyzing.value = false
         stopAnalyzePhase()
@@ -325,7 +340,7 @@ function formatTooltip(fmt: string): string {
       <button
         class="btn-download"
         @click="submitDownload"
-        :disabled="!url.trim() || store.isSubmitting"
+        :disabled="!urlReady || isAnalyzing || store.isSubmitting"
       >
         {{ store.isSubmitting ? 'Submitting…' : 'Download' }}
       </button>
@@ -378,6 +393,10 @@ function formatTooltip(fmt: string): string {
       </div>
     </div>
 
+    <div v-if="analyzeError" class="extract-error">
+      {{ analyzeError }}
+    </div>
+
     <div v-if="extractError" class="extract-error">
       {{ extractError }}
     </div>