feat: enable document orientation detection for scanned PDFs

- Enable PP-StructureV3's use_doc_orientation_classify feature
- Detect rotation angle from doc_preprocessor_res.angle
- Swap page dimensions (width <-> height) for 90°/270° rotations
- Output PDF now correctly displays landscape-scanned content

Also includes:
- Archive completed openspec proposals
- Add simplify-frontend-ocr-config proposal (pending)
- Code cleanup and frontend simplification

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/pages/ProcessingPage.tsx

@@ -12,13 +12,11 @@ import { Play, CheckCircle, FileText, AlertCircle, Clock, Activity, Loader2 } fr
 import LayoutModelSelector from '@/components/LayoutModelSelector'
 import PreprocessingSettings from '@/components/PreprocessingSettings'
 import PreprocessingPreview from '@/components/PreprocessingPreview'
-import TableDetectionSelector from '@/components/TableDetectionSelector'
 import ProcessingTrackSelector from '@/components/ProcessingTrackSelector'
-import OCRPresetSelector from '@/components/OCRPresetSelector'
 import TaskNotFound from '@/components/TaskNotFound'
 import { useTaskValidation } from '@/hooks/useTaskValidation'
 import { useTaskStore, useProcessingState } from '@/store/taskStore'
-import type { LayoutModel, ProcessingOptions, PreprocessingMode, PreprocessingConfig, TableDetectionConfig, ProcessingTrack, OCRPreset, OCRConfig } from '@/types/apiV2'
+import type { LayoutModel, ProcessingOptions, PreprocessingMode, PreprocessingConfig, ProcessingTrack } from '@/types/apiV2'
 
 export default function ProcessingPage() {
   const { t } = useTranslation()
@@ -27,7 +25,9 @@ export default function ProcessingPage() {
 
   // Use TaskStore for processing state management
   const { startProcessing, stopProcessing, updateTaskStatus } = useTaskStore()
-  const processingState = useProcessingState()
+  // processingState is available for future use (e.g., displaying global processing status)
+  const _processingState = useProcessingState()
+  void _processingState // Suppress unused variable warning
 
   // Use shared hook for task validation
   const { taskId, taskDetail, isLoading: isValidating, isNotFound, clearAndReset } = useTaskValidation({
@@ -56,20 +56,9 @@ export default function ProcessingPage() {
   })
   const [showPreview, setShowPreview] = useState(false)
 
-  // Table detection state
-  const [tableDetectionConfig, setTableDetectionConfig] = useState<TableDetectionConfig>({
-    enable_wired_table: true,
-    enable_wireless_table: true,
-    enable_region_detection: true,
-  })
-
   // Processing track override state (null = use system recommendation)
   const [forceTrack, setForceTrack] = useState<ProcessingTrack | null>(null)
 
-  // OCR Preset state (default to 'datasheet' for best balance)
-  const [ocrPreset, setOcrPreset] = useState<OCRPreset>('datasheet')
-  const [ocrConfig, setOcrConfig] = useState<OCRConfig>({})
-
   // Analyze document to determine if OCR is needed (only for pending tasks)
   const { data: documentAnalysis, isLoading: isAnalyzing } = useQuery({
     queryKey: ['documentAnalysis', taskId],
@@ -91,6 +80,8 @@ export default function ProcessingPage() {
     ))
 
   // Start OCR processing
+  // NOTE: Simple OCR mode - using backend defaults for table/chart/formula recognition
+  // Only layout_model and preprocessing options are configurable from frontend
   const processOCRMutation = useMutation({
     mutationFn: () => {
       const options: ProcessingOptions = {
@@ -100,9 +91,7 @@ export default function ProcessingPage() {
         layout_model: layoutModel,
         preprocessing_mode: preprocessingMode,
         preprocessing_config: preprocessingMode === 'manual' ? preprocessingConfig : undefined,
-        table_detection: tableDetectionConfig,
-        ocr_preset: ocrPreset,
-        ocr_config: ocrPreset === 'custom' ? ocrConfig : undefined,
+        // NOTE: table_detection, ocr_preset, ocr_config removed - using backend defaults
       }
 
       // Update TaskStore processing state
@@ -448,15 +437,6 @@ export default function ProcessingPage() {
           {/* OCR Track Options - Only show when document needs OCR */}
           {needsOcrTrack && !isAnalyzing && (
             <>
-              {/* OCR Processing Preset - Primary selection */}
-              <OCRPresetSelector
-                value={ocrPreset}
-                onChange={setOcrPreset}
-                customConfig={ocrConfig}
-                onCustomConfigChange={setOcrConfig}
-                disabled={processOCRMutation.isPending}
-              />
-
               {/* Layout Model Selection */}
               <LayoutModelSelector
                 value={layoutModel}
@@ -464,13 +444,6 @@ export default function ProcessingPage() {
                 disabled={processOCRMutation.isPending}
               />
 
-              {/* Table Detection Settings */}
-              <TableDetectionSelector
-                value={tableDetectionConfig}
-                onChange={setTableDetectionConfig}
-                disabled={processOCRMutation.isPending}
-              />
-
               {/* Preprocessing Settings */}
               <PreprocessingSettings
                 mode={preprocessingMode}