Derive stable prompt sessions for CLI runs

internal/cli/run_contract_test.go

@@ -492,17 +492,28 @@ func TestEffectiveLLMProfileIDsAreSortedDeduplicatedAndLLMOnly(t *testing.T) {
 	}
 }
 
-func TestRunSessionIDUsesExplicitValueOrSourceDocumentID(t *testing.T) {
+func TestRunSessionIDUsesEffectiveValueForPromptRequests(t *testing.T) {
 	for _, tt := range []struct {
 		name string
 		args []string
 		want string
 	}{
-		{name: "source document", want: "source"},
+		{name: "derived default"},
 		{name: "explicit trimmed value", args: []string{"--session-id", " explicit-session "}, want: "explicit-session"},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
 			roots := newStateTestRoots(t)
+			want := tt.want
+			if want == "" {
+				rawInput, err := os.ReadFile(roots.input)
+				if err != nil {
+					t.Fatal(err)
+				}
+				want, err = resolvePromptSessionID("", "test/input", rawInput)
+				if err != nil {
+					t.Fatal(err)
+				}
+			}
 			harness := newStateTestHarness()
 			args := append([]string{"run", "sample", "--config", roots.config, "--input", roots.input, "--chunk_cache", "bypass"}, tt.args...)
 			var stdout, stderr bytes.Buffer
@@ -517,8 +528,8 @@ func TestRunSessionIDUsesExplicitValueOrSourceDocumentID(t *testing.T) {
 				t.Fatalf("session IDs = %#v, want all prompt-facing module requests", sessions)
 			}
 			for _, session := range sessions {
-				if session != tt.want {
-					t.Fatalf("session IDs = %#v, want %q", sessions, tt.want)
+				if session != want {
+					t.Fatalf("session IDs = %#v, want %q", sessions, want)
 				}
 			}
 		})