Add crop refinement, finger removal, and local LLM naming

- vision/refine.py: tighten crops to the paper band (removes mat
  margins and hands beside receipts) and inpaint border-connected
  skin regions so fingers disappear from output
- llm/vision.py: identify documents with a local Ollama vision model
  (qwen2.5vl); extracts vendor/date/total/form code and flags quality
  issues (fingers, blur, glare); falls back to Tesseract when down
- pipeline: drop blank pages, dedupe consecutive captures of the same
  document, record refine/LLM fields in report and export summary

tests/test_orient.py

@@ -0,0 +1,77 @@
+"""End-to-end orientation-detection tests against synthetic text pages.
+
+Skipped automatically if the tesseract binary isn't installed.
+"""
+
+from __future__ import annotations
+
+import shutil
+
+import cv2
+import numpy as np
+import pytest
+from PIL import Image, ImageDraw, ImageFont
+
+from paperpod.vision.orient import apply_rotation, auto_rotate
+
+pytestmark = pytest.mark.skipif(
+    shutil.which("tesseract") is None, reason="tesseract binary not installed"
+)
+
+_FONT_CANDIDATES = [
+    "/System/Library/Fonts/Helvetica.ttc",
+    "/System/Library/Fonts/Supplemental/Arial.ttf",
+]
+
+
+def _font(size: int) -> ImageFont.FreeTypeFont | ImageFont.ImageFont:
+    for path in _FONT_CANDIDATES:
+        try:
+            return ImageFont.truetype(path, size)
+        except OSError:
+            continue
+    return ImageFont.load_default()
+
+
+def _text_page() -> np.ndarray:
+    """A tall white page with a few lines of real words (upright, 0 degrees).
+
+    Rendered with a real TrueType font (not cv2.putText's blocky stroke
+    font), which produces normal glyph shapes; cv2.putText text fragments
+    into dozens of spurious single-character "words" when rotated sideways,
+    which isn't representative of real documents/photos.
+    """
+    img = Image.new("RGB", (400, 600), (255, 255, 255))
+    draw = ImageDraw.Draw(img)
+    font = _font(22)
+    lines = [
+        "INVOICE FROM ACME CORP",
+        "Date: January 5, 2024",
+        "Description of services rendered",
+        "Thank you for your business",
+        "Please remit payment within 30 days",
+    ]
+    for i, line in enumerate(lines):
+        draw.text((20, 80 + i * 60), line, fill=(0, 0, 0), font=font)
+    return cv2.cvtColor(np.array(img), cv2.COLOR_RGB2BGR)
+
+
+@pytest.mark.parametrize("applied_rotation", [0, 90, 180, 270])
+def test_auto_rotate_corrects_known_rotation(applied_rotation):
+    """Rotating upright text by N clockwise needs (360-N) clockwise to undo."""
+    upright = _text_page()
+    rotated_input = apply_rotation(upright, applied_rotation)
+    corrected, result = auto_rotate(rotated_input)
+    assert result.rotation == (360 - applied_rotation) % 360
+    assert corrected.shape == upright.shape
+
+
+def test_apply_rotation_identity_at_zero():
+    page = _text_page()
+    assert np.array_equal(apply_rotation(page, 0), page)
+
+
+def test_apply_rotation_180_is_involutive():
+    page = _text_page()
+    twice = apply_rotation(apply_rotation(page, 180), 180)
+    assert np.array_equal(twice, page)