fix(ids): legacy-id detector only inspects file-level nodes (no Go false-positive)

The graph_has_legacy_ids nudge flagged fresh v9 graphs that contain Go code,
because the Go extractor scopes a type node by package directory
(_make_id(pkg_dir, name) -> "sub_thing"), which coincides with the OLD one-parent
file-stem form of pkg/sub/thing.go even though it's a current, by-design
package-scoped id (methods on a type across files in a package share one node).

The detector now inspects only file-level nodes (source_location "L1"), whose id is
unambiguously the file stem and which the migration actually re-keys. This still
catches a genuine pre-#1504 graph (its file nodes carry the old stem) while leaving
package/dir-scoped symbol ids alone. Verified end-to-end: a fresh Go graph no longer
triggers the rebuild nudge; a real legacy graph still does.

The migration itself was already correct — file nodes and Python/AST symbols
migrate to full-path ids; Go's package-scoped type ids are intentional and
unaffected. This only fixes the over-eager warning.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

graphify/build.py

@@ -201,15 +201,20 @@ def graph_has_legacy_ids(nodes: list, root: str | Path | None = None, sample: in
     stem) rather than the full repo-relative path. Read-only consumers (query,
     serve) use this to nudge the user to rebuild, since they don't re-extract.
 
-    Heuristic and cheap: samples nodes with a relative ``source_file`` and returns
-    True as soon as one ID matches an OLD stem form but NOT the canonical full-path
-    form. Absolute/sourceless nodes are skipped (can't be classified)."""
+    Heuristic and cheap: only **file-level** nodes (source_location ``L1``) are
+    inspected, because their ID is unambiguously the file stem. Symbol nodes are
+    skipped — some extractors scope a symbol by package/directory (Go's
+    ``_make_id(pkg_dir, name)`` → ``sub_thing``), which can coincide with an old
+    file-stem form and would otherwise false-positive. Returns True as soon as one
+    file node's ID matches an OLD stem form but not the canonical full-path form."""
     from graphify.extractors.base import _file_stem
     _r = str(root) if root is not None else None
     checked = 0
     for node in nodes:
         if not isinstance(node, dict):
             continue
+        if str(node.get("source_location") or "") != "L1":
+            continue  # only file-level nodes carry an unambiguous file-stem ID
         nid = node.get("id")
         sf = node.get("source_file")
         if not nid or not isinstance(nid, str) or not sf:

tests/test_build.py

@@ -726,13 +726,18 @@ def test_graph_has_legacy_ids_detects_old_scheme():
     """The read-only-consumer nudge (query/serve) flags a pre-#1504 graph and
     leaves a canonical one alone."""
     from graphify.build import graph_has_legacy_ids
-    old = [{"id": "api_readme", "source_file": "docs/v1/api/README.md", "type": "document"}]
-    new = [{"id": "docs_v1_api_readme", "source_file": "docs/v1/api/README.md", "type": "document"}]
+    old = [{"id": "api_readme", "source_file": "docs/v1/api/README.md", "type": "document", "source_location": "L1"}]
+    new = [{"id": "docs_v1_api_readme", "source_file": "docs/v1/api/README.md", "type": "document", "source_location": "L1"}]
     assert graph_has_legacy_ids(old, root=".") is True
     assert graph_has_legacy_ids(new, root=".") is False
-    # sourceless / top-level nodes don't false-positive
-    assert graph_has_legacy_ids([{"id": "setup", "source_file": "setup.py"}], root=".") is False
+    # sourceless / top-level file nodes don't false-positive
+    assert graph_has_legacy_ids([{"id": "setup", "source_file": "setup.py", "source_location": "L1"}], root=".") is False
     assert graph_has_legacy_ids([{"id": "x", "label": "y"}], root=".") is False
+    # package/dir-scoped SYMBOL ids (Go's _make_id(pkg_dir, name) -> "sub_thing") must
+    # NOT false-positive: not file-level (no L1), so ignored even though "sub_thing"
+    # coincides with the old file-stem form of pkg/sub/thing.go.
+    go_symbol = [{"id": "sub_thing", "source_file": "pkg/sub/thing.go", "type": "code", "source_location": "L3"}]
+    assert graph_has_legacy_ids(go_symbol, root=".") is False
 
 
 def test_semantic_rekey_relative_vs_absolute_source_file():