fix(filesystem): delay register side effects until insert

Write projection and raw side effects only after a successful catalog insert, and clean owned artifacts when registration fails.

tests/test_pifs_register_side_effects.py

@@ -0,0 +1,60 @@
+from pathlib import Path
+
+import pytest
+
+
+class SummaryGenerator:
+    def generate(self, document, *, fields):
+        return {field: "Generated registration summary." for field in fields}
+
+
+class RecordingSummaryIndexer:
+    def __init__(self):
+        self.upserted = []
+
+    def upsert_summary(self, record):
+        self.upserted.append(dict(record))
+        return {"status": "ready"}
+
+
+def test_register_insert_failure_cleans_owned_artifacts_and_skips_projection(
+    tmp_path: Path, monkeypatch
+):
+    from pageindex.filesystem import PageIndexFileSystem
+
+    workspace = tmp_path / "workspace"
+    source = tmp_path / "source.txt"
+    source.write_text("Plain text content for registration.", encoding="utf-8")
+    indexer = RecordingSummaryIndexer()
+    filesystem = PageIndexFileSystem(
+        workspace=workspace,
+        metadata_generator=SummaryGenerator(),
+        summary_projection_indexer=indexer,
+    )
+
+    def fail_insert(records):
+        raise RuntimeError("catalog insert failed")
+
+    monkeypatch.setattr(filesystem.store, "insert_files", fail_insert)
+
+    with pytest.raises(RuntimeError, match="catalog insert failed"):
+        filesystem.register_file(
+            storage_uri=source.as_uri(),
+            source_path="docs/source.txt",
+            folder_path="/documents",
+            external_id="doc_insert_failure",
+            title="Insert failure",
+            content=source.read_text(encoding="utf-8"),
+            metadata_policy={
+                "fields": {
+                    "summary": True,
+                    "doc_type": False,
+                    "domain": False,
+                    "topic": False,
+                }
+            },
+        )
+
+    assert indexer.upserted == []
+    assert list((workspace / "artifacts" / "raw").glob("*.json")) == []
+    assert list((workspace / "artifacts" / "text").glob("*.txt")) == []