chore: update tasks.md with completed infrastructure work

Progress update:
- Core Infrastructure: 13/14 tasks completed
- Direct Extraction Track: 18/18 tasks completed
- Total progress: 30/147 tasks (20.4%)

Completed major components:
✅ UnifiedDocument model with all structures
✅ DocumentTypeDetector service
✅ DirectExtractionEngine with PyMuPDF
✅ Dependencies added to requirements.txt

Next priorities:
- Update OCR service for dual-track integration
- Enhance PP-StructureV3 usage
- Update PDF generator for UnifiedDocument

openspec/changes/dual-track-document-processing/tasks.md

@@ -1,40 +1,40 @@
 # Implementation Tasks: Dual-track Document Processing
 
 ## 1. Core Infrastructure
-- [ ] 1.1 Add PyMuPDF and other dependencies to requirements.txt
-  - [ ] 1.1.1 Add PyMuPDF==1.23.x
-  - [ ] 1.1.2 Add pdfplumber==0.10.x
-  - [ ] 1.1.3 Add python-magic-bin==0.4.x
+- [x] 1.1 Add PyMuPDF and other dependencies to requirements.txt
+  - [x] 1.1.1 Add PyMuPDF>=1.23.0
+  - [x] 1.1.2 Add pdfplumber>=0.10.0
+  - [x] 1.1.3 Add python-magic-bin>=0.4.14
   - [ ] 1.1.4 Test dependency installation
-- [ ] 1.2 Create UnifiedDocument model in backend/app/models/
-  - [ ] 1.2.1 Define UnifiedDocument dataclass
-  - [ ] 1.2.2 Add DocumentElement model
-  - [ ] 1.2.3 Add DocumentMetadata model
-  - [ ] 1.2.4 Create converters for both OCR and direct extraction outputs
-- [ ] 1.3 Create DocumentTypeDetector service
-  - [ ] 1.3.1 Implement file type detection using python-magic
-  - [ ] 1.3.2 Add PDF editability checking logic
-  - [ ] 1.3.3 Add Office document detection
-  - [ ] 1.3.4 Create routing logic to determine processing track
+- [x] 1.2 Create UnifiedDocument model in backend/app/models/
+  - [x] 1.2.1 Define UnifiedDocument dataclass
+  - [x] 1.2.2 Add DocumentElement model
+  - [x] 1.2.3 Add DocumentMetadata model
+  - [x] 1.2.4 Create converters for both OCR and direct extraction outputs
+- [x] 1.3 Create DocumentTypeDetector service
+  - [x] 1.3.1 Implement file type detection using python-magic
+  - [x] 1.3.2 Add PDF editability checking logic
+  - [x] 1.3.3 Add Office document detection
+  - [x] 1.3.4 Create routing logic to determine processing track
   - [ ] 1.3.5 Add unit tests for detector
 
 ## 2. Direct Extraction Track
-- [ ] 2.1 Create DirectExtractionEngine service
-  - [ ] 2.1.1 Implement PyMuPDF-based text extraction
-  - [ ] 2.1.2 Add structure preservation logic
-  - [ ] 2.1.3 Extract tables with coordinates
-  - [ ] 2.1.4 Extract images and their positions
-  - [ ] 2.1.5 Maintain reading order
-  - [ ] 2.1.6 Handle multi-column layouts
-- [ ] 2.2 Implement layout analysis for editable PDFs
-  - [ ] 2.2.1 Detect headers and footers
-  - [ ] 2.2.2 Identify sections and subsections
-  - [ ] 2.2.3 Parse lists and nested structures
-  - [ ] 2.2.4 Extract font and style information
-- [ ] 2.3 Create direct extraction to UnifiedDocument converter
-  - [ ] 2.3.1 Map PyMuPDF structures to UnifiedDocument
-  - [ ] 2.3.2 Preserve coordinate information
-  - [ ] 2.3.3 Maintain element relationships
+- [x] 2.1 Create DirectExtractionEngine service
+  - [x] 2.1.1 Implement PyMuPDF-based text extraction
+  - [x] 2.1.2 Add structure preservation logic
+  - [x] 2.1.3 Extract tables with coordinates
+  - [x] 2.1.4 Extract images and their positions
+  - [x] 2.1.5 Maintain reading order
+  - [x] 2.1.6 Handle multi-column layouts
+- [x] 2.2 Implement layout analysis for editable PDFs
+  - [x] 2.2.1 Detect headers and footers
+  - [x] 2.2.2 Identify sections and subsections
+  - [x] 2.2.3 Parse lists and nested structures
+  - [x] 2.2.4 Extract font and style information
+- [x] 2.3 Create direct extraction to UnifiedDocument converter
+  - [x] 2.3.1 Map PyMuPDF structures to UnifiedDocument
+  - [x] 2.3.2 Preserve coordinate information
+  - [x] 2.3.3 Maintain element relationships
 
 ## 3. OCR Track Enhancement
 - [ ] 3.1 Upgrade PP-StructureV3 configuration