Share prompt instructions and simplify validation helpers

internal/prompts/registry_test.go

@@ -25,6 +25,9 @@ func TestEmbeddedDefinitionsPrepareThroughPromptKit(t *testing.T) {
 		"SectionJSON":                "{\"text\":\"fixture-section\"}",
 		"PayloadJSON":                "[{\"text\":\"fixture-correction\"}]",
 	}
+	for key, value := range SharedVariables() {
+		vars[key] = value
+	}
 	for _, tc := range []struct{ id, instruction, schema, payload string }{
 		{PromptIDModuleGlossaryProposal, "strongly supported by the glossary", "correction_set.v1.json", "fixture-section"},
 		{PromptIDModuleHomophonesProposal, "homophone correction assistant", "correction_set.v1.json", "fixture-section"},
@@ -54,6 +57,24 @@ func TestEmbeddedDefinitionsPrepareThroughPromptKit(t *testing.T) {
 			if strings.HasPrefix(tc.id, "modules.") && !strings.Contains(rendered, "fixture-glossary") {
 				t.Error("missing glossary context")
 			}
+			contract := "ValidationContract"
+			if strings.HasPrefix(tc.id, "modules.") {
+				contract = "ProposalContract"
+			}
+			for _, line := range strings.Split(strings.TrimSpace(vars[contract]), "\n") {
+				if strings.Count(rendered, line) != 1 {
+					t.Errorf("shared instruction missing or duplicated: %q", line)
+				}
+			}
+			for id, guidance := range map[string]string{
+				PromptIDModuleGlossaryProposal:   "every literal occurrence",
+				PromptIDModuleSpokenWordProposal: "Accidental repetition of a protected name may be reduced",
+				PromptIDModuleGrammarProposal:    "whole-word article",
+			} {
+				if tc.id == id && !strings.Contains(rendered, guidance) {
+					t.Errorf("missing module guidance: %s", guidance)
+				}
+			}
 			missing := map[string]string{"HardeningPolicy": HardeningText()}
 			if _, err := engine.Prepare(context.Background(), pk.RunRequest{PromptID: tc.id, PromptVersion: VersionV1, ProfileID: "fixture", Vars: missing}); err == nil {
 				t.Error("missing variables accepted")