chore: backup before code cleanup

Backup commit before executing remove-unused-code proposal.
This includes all pending changes and new features.

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

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

openspec/changes/simple-text-positioning/design.md

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+# Design: Simple Text Positioning
+
+## Architecture
+
+### Current Flow (Complex)
+```
+Raw OCR → PP-Structure Analysis → Table Detection → HTML Parsing →
+Column Correction → Cell Positioning → PDF Generation
+```
+
+### New Flow (Simple)
+```
+Raw OCR → Text Region Extraction → Bbox Processing →
+Rotation Calculation → Font Size Estimation → PDF Text Rendering
+```
+
+## Core Components
+
+### 1. TextRegionRenderer
+
+New service class to handle raw OCR text rendering:
+
+```python
+class TextRegionRenderer:
+    """Render raw OCR text regions to PDF."""
+
+    def render_text_region(
+        self,
+        canvas: Canvas,
+        region: Dict,
+        scale_factor: float
+    ) -> None:
+        """
+        Render a single OCR text region.
+
+        Args:
+            canvas: ReportLab canvas
+            region: Raw OCR region with text and bbox
+            scale_factor: Coordinate scaling factor
+        """
+```
+
+### 2. Bbox Processing
+
+Raw OCR bbox format (quadrilateral - 4 corner points):
+```json
+{
+  "text": "LOCTITE",
+  "bbox": [[116, 76], [378, 76], [378, 128], [116, 128]],
+  "confidence": 0.98
+}
+```
+
+Processing steps:
+1. **Center point**: Average of 4 corners
+2. **Width/Height**: Distance between corners
+3. **Rotation angle**: Angle of top edge from horizontal
+4. **Font size**: Approximate from bbox height
+
+### 3. Rotation Calculation
+
+```python
+def calculate_rotation(bbox: List[List[float]]) -> float:
+    """
+    Calculate text rotation from bbox quadrilateral.
+
+    Returns angle in degrees (counter-clockwise from horizontal).
+    """
+    # Top-left to top-right vector
+    dx = bbox[1][0] - bbox[0][0]
+    dy = bbox[1][1] - bbox[0][1]
+
+    # Angle in degrees
+    angle = math.atan2(dy, dx) * 180 / math.pi
+    return angle
+```
+
+### 4. Font Size Estimation
+
+```python
+def estimate_font_size(bbox: List[List[float]], text: str) -> float:
+    """
+    Estimate font size from bbox dimensions.
+
+    Uses bbox height as primary indicator, adjusted for aspect ratio.
+    """
+    # Calculate bbox height (average of left and right edges)
+    left_height = math.dist(bbox[0], bbox[3])
+    right_height = math.dist(bbox[1], bbox[2])
+    avg_height = (left_height + right_height) / 2
+
+    # Font size is approximately 70-80% of bbox height
+    return avg_height * 0.75
+```
+
+## Integration Points
+
+### PDFGeneratorService
+
+Modify `draw_ocr_content()` to use simple text positioning:
+
+```python
+def draw_ocr_content(self, canvas, content_data, page_info):
+    """Draw OCR content using simple text positioning."""
+
+    # Use raw OCR regions directly
+    raw_regions = content_data.get('raw_ocr_regions', [])
+
+    for region in raw_regions:
+        self.text_renderer.render_text_region(
+            canvas, region, scale_factor
+        )
+```
+
+### Configuration
+
+Add config option to enable/disable simple mode:
+
+```python
+class OCRSettings:
+    simple_text_positioning: bool = Field(
+        default=True,
+        description="Use simple text positioning instead of table reconstruction"
+    )
+```
+
+## File Changes
+
+| File | Change |
+|------|--------|
+| `app/services/text_region_renderer.py` | New - Text rendering logic |
+| `app/services/pdf_generator_service.py` | Modify - Integration |
+| `app/core/config.py` | Add - Configuration option |
+
+## Edge Cases
+
+1. **Overlapping text**: Regions may overlap slightly - render in reading order
+2. **Very small text**: Minimum font size threshold (6pt)
+3. **Rotated pages**: Handle 90/180/270 degree page rotation
+4. **Empty regions**: Skip regions with empty text
+5. **Unicode text**: Ensure font supports CJK characters

openspec/changes/simple-text-positioning/proposal.md

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+# Simple Text Positioning from Raw OCR
+
+## Summary
+
+Simplify OCR track PDF generation by rendering raw OCR text at correct positions without complex table structure reconstruction.
+
+## Problem
+
+Current OCR track processing has multiple failure points:
+1. PP-Structure table structure recognition fails for borderless tables
+2. Multi-column layouts get merged incorrectly into single tables
+3. Table HTML reconstruction produces wrong cell positions
+4. Complex column correction algorithms still can't fix fundamental structure errors
+
+Meanwhile, raw OCR (`raw_ocr_regions.json`) correctly identifies all text with accurate bounding boxes.
+
+## Solution
+
+Replace complex table reconstruction with simple text positioning:
+1. Read raw OCR regions directly
+2. Position text at bbox coordinates
+3. Calculate text rotation from bbox quadrilateral shape
+4. Estimate font size from bbox height
+5. Skip table HTML parsing entirely for OCR track
+
+## Benefits
+
+- **Reliability**: Raw OCR text positions are accurate
+- **Simplicity**: Eliminates complex table parsing logic
+- **Performance**: Faster processing without structure analysis
+- **Consistency**: Predictable output regardless of table type
+
+## Trade-offs
+
+- No table borders in output
+- No cell structure (colspan, rowspan)
+- Visual layout approximation rather than semantic structure
+
+## Scope
+
+- OCR track PDF generation only
+- Direct track remains unchanged (uses native PDF text extraction)

openspec/changes/simple-text-positioning/tasks.md

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+# Tasks: Simple Text Positioning
+
+## Phase 1: Core Implementation
+
+- [x] Create `TextRegionRenderer` class in `app/services/text_region_renderer.py`
+  - [x] Implement `calculate_rotation()` from bbox quadrilateral
+  - [x] Implement `estimate_font_size()` from bbox height
+  - [x] Implement `render_text_region()` main method
+  - [x] Handle coordinate system transformation (OCR → PDF)
+
+## Phase 2: Integration
+
+- [x] Add `simple_text_positioning_enabled` config option
+- [x] Modify `PDFGeneratorService._generate_ocr_track_pdf()` to use `TextRegionRenderer`
+- [x] Ensure raw OCR regions are loaded correctly via `load_raw_ocr_regions()`
+
+## Phase 3: Image/Chart/Formula Support
+
+- [x] Add image element type detection (`figure`, `image`, `chart`, `seal`, `formula`)
+- [x] Render image elements from UnifiedDocument to PDF
+- [x] Handle image path resolution (result_dir, imgs/ subdirectory)
+- [x] Coordinate transformation for image placement
+
+## Phase 4: Text Straightening & Overlap Avoidance
+
+- [x] Add rotation straightening threshold (default 10°)
+  - Small rotation angles (< 10°) are treated as 0° for clean output
+  - Only significant rotations (e.g., 90°) are preserved
+- [x] Add IoA (Intersection over Area) overlap detection
+  - IoA threshold default 0.3 (30% overlap triggers skip)
+  - Text regions overlapping with images/charts are skipped
+- [x] Collect exclusion zones from image elements
+- [x] Pass exclusion zones to text renderer
+
+## Phase 5: Chart Axis Label Deduplication
+
+- [x] Add `is_axis_label()` method to detect axis labels
+  - Y-axis: Vertical text immediately left of chart
+  - X-axis: Horizontal text immediately below chart
+- [x] Add `is_near_zone()` method for proximity checking
+- [x] Position-aware deduplication in `render_text_region()`
+  - Collect texts inside zones + axis labels
+  - Skip matching text only if near zone or is axis label
+  - Preserve matching text far from zones (e.g., table values)
+- [x] Test results:
+  - "Temperature, C" and "Syringe Thaw Time, Minutes" correctly skipped
+  - Table values like "10" at top of page correctly rendered
+  - Page 2: 128/148 text regions rendered (12 overlap + 8 dedupe)
+
+## Phase 6: Testing
+
+- [x] Test with scan.pdf task (064e2d67-338c-4e54-b005-204c3b76fe63)
+  - Page 2: Chart image rendered, axis labels deduplicated
+  - PDF is searchable and selectable
+  - Text is properly straightened (no skew artifacts)
+- [ ] Compare output quality vs original scan visually
+- [ ] Test with documents containing seals/formulas