feat: per-extraction OCR language override

Allow users to specify a Tesseract language string (e.g. jpn+jpn_vert)
on a per-extraction basis, overriding the global OCR language setting.

- Add payload column to ai_jobs table (migration) to carry per-call data
- Thread ocrLanguages payload through enqueueJob → processNextJob → extractItemText
- New GET /api/ai-settings/ocr endpoint (requireAuth) returns { ocrMode, ocrLanguages }
- ImageLightbox fetches OCR settings and shows a language input next to the
  Extract Text button when mode is hybrid or tesseract (hidden for llm-only)
- MixedView fetches OCR settings and passes them down to EntryTile; kebab
  Extract Text on images shows an inline language prompt before dispatching the job

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/api/ai-settings/ocr/route.ts

@@ -0,0 +1,11 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { requireAuth } from '@/lib/auth'
+import { getAiConfig } from '@/lib/app-settings'
+
+export async function GET(request: NextRequest) {
+  const auth = await requireAuth(request)
+  if (auth instanceof NextResponse) return auth
+
+  const { ocrMode, ocrLanguages } = getAiConfig()
+  return NextResponse.json({ ocrMode, ocrLanguages })
+}

src/app/api/ai-tagging/extract-text/route.ts

@@ -3,14 +3,14 @@ import { requireLibraryAccess } from '@/lib/auth'
 import { enqueueJob } from '@/lib/ai-jobs'
 
 export async function POST(request: NextRequest) {
-  let body: { itemKey?: string }
+  let body: { itemKey?: string; ocrLanguages?: string }
   try {
     body = await request.json()
   } catch {
     return NextResponse.json({ error: 'Invalid JSON body' }, { status: 400 })
   }
 
-  const { itemKey } = body
+  const { itemKey, ocrLanguages } = body
   if (!itemKey || typeof itemKey !== 'string') {
     return NextResponse.json({ error: 'itemKey is required' }, { status: 400 })
   }
@@ -19,6 +19,12 @@ export async function POST(request: NextRequest) {
   const auth = await requireLibraryAccess(request, libraryId)
   if (auth instanceof NextResponse) return auth
 
-  const jobId = enqueueJob(itemKey, 'extract', libraryId)
+  const jobId = enqueueJob(
+    itemKey,
+    'extract',
+    libraryId,
+    undefined,
+    ocrLanguages ? { ocrLanguages } : undefined,
+  )
   return NextResponse.json({ jobId }, { status: 202 })
 }