feat(ocr): populate sidecar_candidates and bundle_source_legend_ids in vnext index

paperforge/worker/ocr_figure_vnext_corpus.py

@@ -87,6 +87,22 @@ class FigureCandidateIndex:
             and ocr_figures._extract_figure_number(str(leg.get("text", "")))
             is not None
         }
+        # Populate sidecar_candidates: pages with ≥2 aligned narrow captions.
+        sidecar_candidates: dict[int, list[dict]] = {}
+        _legends_by_page: dict[int, list[dict]] = {}
+        for leg in formal_legends:
+            _legends_by_page.setdefault(int(leg.get("page", 0) or 0), []).append(leg)
+        for sp, spl in _legends_by_page.items():
+            narrow_set = ocr_figures._same_page_narrow_caption_column(spl, corpus.page_width)
+            if len(narrow_set) >= 2:
+                sidecar_candidates[sp] = narrow_set
+
+        # Populate bundle_source_legend_ids: legends on pages with ≥3 numbered legends
+        # and zero assets on that page.
+        bundle_source_legend_ids = ocr_figures._identify_bundle_source_legend_ids(
+            formal_legends, corpus.raw_assets
+        )
+
         return cls(
             formal_legends=formal_legends,
             held_legends=[],
@@ -94,7 +110,7 @@ class FigureCandidateIndex:
             deduped_legends=formal_legends,
             candidate_groups=candidate_groups,
             competing_caption_pages=competing_caption_pages,
-            sidecar_candidates={},
-            bundle_source_legend_ids=set(),
+            sidecar_candidates=sidecar_candidates,
+            bundle_source_legend_ids=bundle_source_legend_ids,
             locator_candidates=corpus.locator_candidates,
         )

tests/test_ocr_figure_vnext_corpus.py

@@ -86,3 +86,117 @@ def test_rejected_legends_excluded_from_candidate_group_semantics() -> None:
             assert group.get("page_legend_count") == 1, (
                 f"Expected page_legend_count=1 (formal legends only), got {group.get('page_legend_count')}"
             )
+
+
+def test_candidate_index_populates_sidecar_candidates_for_narrow_caption_page() -> None:
+    """Three narrow numbered captions on one page → sidecar_candidates has that page."""
+    blocks = [
+        # Three narrow formal legends on page 5 — width=200, aligned at x-center=200
+        {
+            "block_id": "leg1",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 1. A caption",
+            "bbox": [100, 100, 300, 120],
+        },
+        {
+            "block_id": "leg2",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 2. Another caption",
+            "bbox": [100, 130, 300, 150],
+        },
+        {
+            "block_id": "leg3",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 3. Yet another caption",
+            "bbox": [100, 160, 300, 180],
+        },
+        # One asset on page 5 so page has assets
+        {
+            "block_id": "ast1",
+            "page": 5,
+            "role": "figure_asset",
+            "bbox": [0, 200, 400, 500],
+        },
+    ]
+    corpus = FigureCorpus.from_blocks(blocks, page_width=1200)
+    index = FigureCandidateIndex.from_corpus(corpus)
+    assert 5 in index.sidecar_candidates
+    assert len(index.sidecar_candidates[5]) >= 2
+
+
+def test_candidate_index_populates_bundle_source_legend_ids() -> None:
+    """Three numbered legends on a page with zero assets → bundle source ids populated."""
+    blocks = [
+        # Three numbered legends on page 3 — no assets on page 3
+        {
+            "block_id": "leg1",
+            "page": 3,
+            "role": "figure_caption",
+            "text": "Figure 1. Caption A",
+            "bbox": [100, 100, 500, 120],
+        },
+        {
+            "block_id": "leg2",
+            "page": 3,
+            "role": "figure_caption",
+            "text": "Figure 2. Caption B",
+            "bbox": [100, 130, 500, 150],
+        },
+        {
+            "block_id": "leg3",
+            "page": 3,
+            "role": "figure_caption",
+            "text": "Figure 3. Caption C",
+            "bbox": [100, 160, 500, 180],
+        },
+        # Assets on other pages
+        {
+            "block_id": "ast1",
+            "page": 4,
+            "role": "figure_asset",
+            "bbox": [0, 0, 400, 300],
+        },
+        {
+            "block_id": "ast2",
+            "page": 5,
+            "role": "figure_asset",
+            "bbox": [0, 0, 400, 300],
+        },
+    ]
+    corpus = FigureCorpus.from_blocks(blocks, page_width=1200)
+    index = FigureCandidateIndex.from_corpus(corpus)
+    assert len(index.bundle_source_legend_ids) >= 3
+
+
+def test_candidate_index_sidecar_candidates_empty_for_wide_captions() -> None:
+    """Wide captions (width > 720 on page_width=1200) → no sidecar candidates."""
+    blocks = [
+        # Three wide captions on page 5 — width=1000 > 720
+        {
+            "block_id": "leg1",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 1. Widest caption",
+            "bbox": [0, 100, 1000, 120],
+        },
+        {
+            "block_id": "leg2",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 2. Also wide",
+            "bbox": [0, 130, 1000, 150],
+        },
+        {
+            "block_id": "leg3",
+            "page": 5,
+            "role": "figure_caption",
+            "text": "Figure 3. Still wide",
+            "bbox": [0, 160, 1000, 180],
+        },
+    ]
+    corpus = FigureCorpus.from_blocks(blocks, page_width=1200)
+    index = FigureCandidateIndex.from_corpus(corpus)
+    assert index.sidecar_candidates == {}