feat: add configurable download filename patterns

client/src/features/book/components/detail/tabs/DetailsTab.vue

@@ -228,8 +228,7 @@ function openBook() {
 function downloadFile() {
   if (!primaryFile.value) return
   const a = document.createElement('a')
-  a.href = `/api/v1/books/files/${primaryFile.value.id}/serve`
-  a.download = `book.${primaryFile.value.format ?? 'epub'}`
+  a.href = `/api/v1/books/files/${primaryFile.value.id}/serve?download=1`
   a.click()
 }
 

client/src/features/book/components/detail/tabs/FilesTab.vue

@@ -45,8 +45,7 @@ function openFile(file: BookDetailFile) {
 
 function downloadFile(file: BookDetailFile) {
   const a = document.createElement('a')
-  a.href = `/api/v1/books/files/${file.id}/serve`
-  a.download = file.filename ?? `book.${file.format ?? 'epub'}`
+  a.href = `/api/v1/books/files/${file.id}/serve?download=1`
   a.click()
 }
 

client/src/features/reader/components/PdfToolbar.vue

@@ -260,8 +260,7 @@ function currentZoomValue(): string {
     <Tooltip>
       <TooltipTrigger as-child>
         <a
-          :href="`/api/v1/books/files/${fileId}/serve`"
-          download
+          :href="`/api/v1/books/files/${fileId}/serve?download=1`"
           class="viewer-btn flex items-center justify-center"
         >
           <Download :size="14" />
@@ -346,4 +345,3 @@ function currentZoomValue(): string {
     </DropdownMenu>
   </div>
 </template>
-

client/src/features/settings/FileNamingSettings.vue

@@ -1,24 +1,32 @@
 <script setup lang="ts">
 import { onMounted, ref } from 'vue'
 import { Check, ChevronDown, ChevronUp, FileText, Loader2, RotateCcw, Save } from 'lucide-vue-next'
-import { DEFAULT_UPLOAD_PATTERN, PATTERN_TOKENS } from '@projectx/types'
+import { DEFAULT_DOWNLOAD_PATTERN, DEFAULT_UPLOAD_PATTERN, PATTERN_TOKENS } from '@projectx/types'
 import { useFileNamingPattern } from './composables/useFileNamingPattern'
 import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip'
 
 const {
   globalPattern,
   globalError,
+  downloadPattern,
+  downloadError,
   libraries,
   loadingGlobal,
   savingGlobal,
+  loadingDownload,
+  savingDownload,
   savingLibraryId,
   fetchGlobalPattern,
+  fetchDownloadPattern,
   fetchLibraries,
   onGlobalPatternInput,
+  onDownloadPatternInput,
   saveGlobalPattern,
+  saveDownloadPattern,
   saveLibraryPattern,
   clearLibraryPattern,
   getEffectivePreview,
+  previewDownloadName,
   previewPath,
 } = useFileNamingPattern()
 
@@ -50,7 +58,7 @@ const EXAMPLES = [
 ]
 
 onMounted(async () => {
-  await Promise.all([fetchGlobalPattern(), fetchLibraries()])
+  await Promise.all([fetchGlobalPattern(), fetchDownloadPattern(), fetchLibraries()])
 })
 </script>
 
@@ -60,13 +68,13 @@ onMounted(async () => {
     <div>
       <h2 class="settings-title">File Naming</h2>
       <p class="settings-subtitle">
-        Control how uploaded files are named and organized on disk. Patterns apply when a file is uploaded.
+        Control naming patterns for uploads and downloads using the same placeholder syntax.
       </p>
     </div>
 
-    <!-- Global default -->
+    <!-- Upload global default -->
     <div>
-      <p class="settings-group-label">Default Pattern</p>
+      <p class="settings-group-label">Upload Pattern</p>
       <div class="border border-border rounded-lg bg-card px-5 py-5 space-y-4">
         <p class="text-xs text-muted-foreground leading-relaxed">
           Applied to all libraries unless overridden. Leave blank to use the built-in default layout.
@@ -101,6 +109,43 @@ onMounted(async () => {
       </div>
     </div>
 
+    <!-- Download global default -->
+    <div>
+      <p class="settings-group-label">Download Pattern</p>
+      <div class="border border-border rounded-lg bg-card px-5 py-5 space-y-4">
+        <p class="text-xs text-muted-foreground leading-relaxed">
+          Controls suggested filenames for single-file downloads and files inside export ZIPs.
+        </p>
+
+        <div class="space-y-1.5">
+          <div class="flex gap-2">
+            <input
+              :value="downloadPattern"
+              type="text"
+              :placeholder="DEFAULT_DOWNLOAD_PATTERN"
+              class="flex-1 h-8 rounded-md border border-input bg-background px-2.5 text-sm text-foreground placeholder:text-muted-foreground/50 focus:outline-none focus:ring-1 focus:ring-ring"
+              :class="downloadError ? 'border-destructive focus:ring-destructive' : ''"
+              :disabled="loadingDownload"
+              @input="onDownloadPatternInput(($event.target as HTMLInputElement).value)"
+            />
+            <button
+              class="flex items-center gap-1.5 h-8 px-3 rounded-md border border-border bg-background text-sm text-foreground hover:bg-muted transition-colors disabled:opacity-50"
+              :disabled="savingDownload || !!downloadError || loadingDownload"
+              @click="saveDownloadPattern"
+            >
+              <Loader2 v-if="savingDownload" :size="13" class="animate-spin" />
+              <Save v-else :size="13" />
+              Save
+            </button>
+          </div>
+          <p v-if="downloadError" class="text-xs text-destructive">{{ downloadError }}</p>
+          <p class="text-xs text-muted-foreground font-mono">
+            Preview: <span class="text-foreground">{{ previewDownloadName(downloadPattern) }}</span>
+          </p>
+        </div>
+      </div>
+    </div>
+
     <!-- Per-library overrides -->
     <div>
       <p class="settings-group-label">Library Overrides</p>
@@ -229,7 +274,7 @@ onMounted(async () => {
           <p class="text-xs font-medium text-foreground mb-1.5">Folder-only mode</p>
           <p class="text-xs text-muted-foreground">
             End the pattern with <code class="bg-muted px-1 py-0.5 rounded font-mono text-foreground">/</code> to specify a folder only - the
-            original filename is preserved inside it.
+            original filename is preserved inside it. This affects upload destinations and ZIP export paths.
           </p>
         </div>
       </div>

client/src/features/settings/composables/useFileNamingPattern.ts

@@ -1,7 +1,13 @@
 import { ref } from 'vue'
 import { toast } from 'vue-sonner'
 import { api } from '@/lib/api'
-import { EXAMPLE_PATTERN_METADATA, resolveUploadPath, validatePattern } from '@projectx/types'
+import {
+  DEFAULT_DOWNLOAD_PATTERN,
+  EXAMPLE_PATTERN_METADATA,
+  resolveDownloadFilename,
+  resolveUploadPath,
+  validatePattern,
+} from '@projectx/types'
 import type { Library } from '@projectx/types'
 import { useLibraries } from '@/features/library/composables/useLibraries'
 
@@ -14,11 +20,20 @@ export function previewPath(pattern: string): string {
   return resolved.startsWith('/') ? resolved : `/${resolved}`
 }
 
+export function previewDownloadName(pattern: string): string {
+  const resolved = resolveDownloadFilename(pattern || DEFAULT_DOWNLOAD_PATTERN, EXAMPLE_PATTERN_METADATA, 'epub')
+  return resolved || 'neuromancer.epub'
+}
+
 export function useFileNamingPattern() {
   const globalPattern = ref('')
   const globalError = ref('')
   const loadingGlobal = ref(false)
   const savingGlobal = ref(false)
+  const downloadPattern = ref('')
+  const downloadError = ref('')
+  const loadingDownload = ref(false)
+  const savingDownload = ref(false)
   const savingLibraryId = ref<number | null>(null)
 
   const { libraries, fetchLibraries } = useLibraries()
@@ -36,11 +51,29 @@ export function useFileNamingPattern() {
     }
   }
 
+  async function fetchDownloadPattern() {
+    loadingDownload.value = true
+    try {
+      const res = await api('/api/v1/app-settings/download-pattern')
+      if (res.ok) {
+        const data: { pattern: string } = await res.json()
+        downloadPattern.value = data.pattern
+      }
+    } finally {
+      loadingDownload.value = false
+    }
+  }
+
   function onGlobalPatternInput(value: string) {
     globalPattern.value = value
     globalError.value = value && !validatePattern(value) ? 'Pattern contains invalid characters' : ''
   }
 
+  function onDownloadPatternInput(value: string) {
+    downloadPattern.value = value
+    downloadError.value = value && !validatePattern(value) ? 'Pattern contains invalid characters' : ''
+  }
+
   async function saveGlobalPattern() {
     if (globalError.value) return
     savingGlobal.value = true
@@ -60,6 +93,25 @@ export function useFileNamingPattern() {
     }
   }
 
+  async function saveDownloadPattern() {
+    if (downloadError.value) return
+    savingDownload.value = true
+    try {
+      const res = await api('/api/v1/app-settings/download-pattern', {
+        method: 'PUT',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ pattern: downloadPattern.value }),
+      })
+      if (res.ok) {
+        toast.success('Download pattern saved')
+      } else {
+        toast.error('Failed to save download pattern')
+      }
+    } finally {
+      savingDownload.value = false
+    }
+  }
+
   async function saveLibraryPattern(library: Library) {
     savingLibraryId.value = library.id
     try {
@@ -90,17 +142,25 @@ export function useFileNamingPattern() {
   return {
     globalPattern,
     globalError,
+    downloadPattern,
+    downloadError,
     libraries,
     loadingGlobal,
     savingGlobal,
+    loadingDownload,
+    savingDownload,
     savingLibraryId,
     fetchGlobalPattern,
+    fetchDownloadPattern,
     fetchLibraries,
     onGlobalPatternInput,
+    onDownloadPatternInput,
     saveGlobalPattern,
+    saveDownloadPattern,
     saveLibraryPattern,
     clearLibraryPattern,
     getEffectivePreview,
     previewPath,
+    previewDownloadName,
   }
 }