fix(drift): do not treat version-shaped refs as missing paths

src/drift/__tests__/path-false-positives.test.ts

@@ -60,15 +60,20 @@ describe("MISSING_PATH false positives", () => {
     ).toEqual([]);
   });
 
-  // Not part of #143. A trailing version number reads as a file extension to
-  // the guard above, so `release/2.1.0` never reaches the unrooted check and is
-  // reported as a missing path. Tracked separately; unskip with the fix.
-  it.skip("does not claim a version-shaped branch name", () => {
+  it("does not claim a version-shaped branch name", () => {
     expect(
-      missingPaths("# Release\n\n- Work landed on `release/2.1.0` and `python/3.11`\n")
+      missingPaths(
+        "# Release\n\n- Work landed on `release/2.1.0`, `python/3.11`, and `node/20.11`\n"
+      )
     ).toEqual([]);
   });
 
+  it("still claims a missing file with an alphabetic extension", () => {
+    // Tightening the extension check must not treat `docs/foo.bar` as unrooted
+    // prose: `.bar` is a file type, so the claim stays a missing path.
+    expect(missingPaths("# Docs\n\n- See `docs/foo.bar`\n")).toEqual(["docs/foo.bar"]);
+  });
+
   it("does not claim a pseudo-path pair such as overall/overall", () => {
     expect(missingPaths("# Stats\n\n- Rating shown as `overall/overall`\n")).toEqual([]);
   });

src/drift/checkers/path.ts

@@ -94,7 +94,10 @@ function isUnrootedReference(
   const trimmed = value.replace(/\/+$/, "");
   const isDirectoryRef = trimmed !== value;
   if (!trimmed.includes("/") && !isDirectoryRef) return false;
-  if (/\.[A-Za-z0-9]+$/.test(trimmed)) return false;
+  // A trailing numeric-only segment is a version (`release/2.1.0`,
+  // `python/3.11`), not a file type. Require an alphabetic character so
+  // `.ts` still counts as an extension and those tokens reach the prose check.
+  if (/\.[A-Za-z0-9]*[A-Za-z][A-Za-z0-9]*$/.test(trimmed)) return false;
 
   const first = trimmed.split("/")[0];
   if (!first || first.startsWith("@") || first === "." || first === "..") return false;