fix: remove unsafe tests→tested_by alias that inverts edge direction

The "tests" alias silently rewrites to "tested_by" without swapping
source/target, which inverts the relationship meaning and produces
incorrect edges. Direction-inverting aliases should fail validation
so the LLM gets explicit feedback to fix the edge.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

understand-anything-plugin/packages/core/src/__tests__/schema.test.ts

@@ -224,13 +224,12 @@ describe("schema validation", () => {
     expect(result.data!.edges[0].type).toBe("depends_on");
   });
 
-  it('normalizes "tests" edge type to "tested_by"', () => {
+  it('rejects "tests" edge type — direction-inverting alias is unsafe', () => {
     const graph = structuredClone(validGraph);
     (graph.edges[0] as any).type = "tests";
 
     const result = validateGraph(graph);
-    expect(result.success).toBe(true);
-    expect(result.data!.edges[0].type).toBe("tested_by");
+    expect(result.success).toBe(false);
   });
 
   it("still rejects truly invalid edge types after normalization", () => {

understand-anything-plugin/packages/core/src/schema.ts

@@ -31,7 +31,6 @@ export const EDGE_TYPE_ALIASES: Record<string, string> = {
   relates_to: "related",
   related_to: "related",
   similar: "similar_to",
-  tests: "tested_by",
   import: "imports",
   export: "exports",
   contain: "contains",