feat(validator): R1 page_index continuity

tk_comfyui_batch_image/core/validator.py

@@ -41,8 +41,22 @@ def _schema_errors(data: dict) -> list[CheckError]:
     ]
 
 
-_LAYER2_RULES: list[Callable[[dict], list[CheckError]]] = []
-"""Populated by later tasks — keep empty for scaffold task."""
+def r_page_index_continuity(data: dict) -> list[CheckError]:
+    for i, page in enumerate(data.get("pages", [])):
+        expected = i + 1
+        got = page.get("page_index")
+        if got != expected:
+            return [CheckError(
+                layer=2,
+                path=f"pages[{i}].page_index",
+                message=f"expected {expected}, got {got} (pages must be contiguous from 1)",
+            )]
+    return []
+
+
+_LAYER2_RULES: list[Callable[[dict], list[CheckError]]] = [
+    r_page_index_continuity,
+]
 
 
 def _semantic_errors(data: dict) -> list[CheckError]:

tk_comfyui_batch_image/tests/test_validator_layer2.py

@@ -28,6 +28,37 @@ def test_validate_raises_on_invalid_schema():
         validate({})   # empty dict fails schema required-field check
 
 
+def _book_with_pages(page_indexes: list[int]) -> dict:
+    book = _minimal_valid_book()
+    template = book["pages"][0]
+    book["pages"] = [{**template, "page_index": idx} for idx in page_indexes]
+    return book
+
+
+def test_r1_page_index_sequential_from_one_passes():
+    assert collect_errors(_book_with_pages([1, 2, 3])) == []
+
+
+def test_r1_page_index_gap_is_caught():
+    errs = collect_errors(_book_with_pages([1, 3, 4]))
+    assert len(errs) == 1
+    assert errs[0].layer == 2
+    assert errs[0].path == "pages[1].page_index"
+    assert "expected 2" in errs[0].message
+    assert "got 3" in errs[0].message
+
+
+def test_r1_page_index_starts_at_wrong_number():
+    errs = collect_errors(_book_with_pages([2, 3]))
+    assert len(errs) >= 1
+    assert errs[0].path == "pages[0].page_index"
+
+
+def test_r1_page_index_duplicate():
+    errs = collect_errors(_book_with_pages([1, 1]))
+    assert any("pages[1].page_index" in e.path for e in errs)
+
+
 def _minimal_valid_book() -> dict:
     return {
         "version": "1.0",