feat: add shell tool call delta message handling

Implemented the buildShellToolCallDeltaMessage function to map client shell output to the delta format for Cursor's terminal bubble. This includes handling both stdout and stderr events. Updated the service to publish these messages when processing execution results. Additionally, added a test for enabling terminal output UI streaming in the bootstrap statsig configuration.

internal/cursor/state_db_test.go

@@ -0,0 +1,94 @@
+package cursor
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"path/filepath"
+	"testing"
+)
+
+func TestSyncCursorAuthStateDBDisablesCachedTerminalOutputUIStreamingIdempotently(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "state.vscdb")
+	db, err := sql.Open("sqlite", path)
+	if err != nil {
+		t.Fatalf("open temporary state db: %v", err)
+	}
+	if _, err := db.Exec("CREATE TABLE ItemTable (key TEXT UNIQUE ON CONFLICT REPLACE, value BLOB)"); err != nil {
+		db.Close()
+		t.Fatalf("create ItemTable: %v", err)
+	}
+	bootstrap := map[string]any{
+		"feature_gates": map[string]any{
+			"disable_terminal_output_ui_streaming": map[string]any{
+				"value":     true,
+				"rule_id":   "local_enabled",
+				"groupName": "local_enabled",
+			},
+			"unrelated_gate": map[string]any{"value": true},
+		},
+		"hash_used": "none",
+	}
+	raw, err := json.Marshal(bootstrap)
+	if err != nil {
+		db.Close()
+		t.Fatalf("encode bootstrap: %v", err)
+	}
+	if _, err := db.Exec("INSERT INTO ItemTable(key, value) VALUES(?, ?)", cursorStateStatsigBootstrapKey, raw); err != nil {
+		db.Close()
+		t.Fatalf("insert bootstrap: %v", err)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatalf("close setup db: %v", err)
+	}
+
+	values := map[string]string{"cursorAuth/cachedEmail": "local@example.com"}
+	if err := syncCursorAuthStateDB(path, values); err != nil {
+		t.Fatalf("first state sync: %v", err)
+	}
+	first := readCursorStatsigBootstrapForTest(t, path)
+	assertCursorStatsigGateValueForTest(t, first, "disable_terminal_output_ui_streaming", false)
+	assertCursorStatsigGateValueForTest(t, first, "unrelated_gate", true)
+
+	if err := syncCursorAuthStateDB(path, values); err != nil {
+		t.Fatalf("second state sync: %v", err)
+	}
+	second := readCursorStatsigBootstrapForTest(t, path)
+	if string(second) != string(first) {
+		t.Fatalf("repeated sync changed bootstrap:\nfirst:  %s\nsecond: %s", first, second)
+	}
+}
+
+func readCursorStatsigBootstrapForTest(t *testing.T, path string) []byte {
+	t.Helper()
+	db, err := sql.Open("sqlite", path)
+	if err != nil {
+		t.Fatalf("open state db: %v", err)
+	}
+	defer db.Close()
+
+	var raw []byte
+	if err := db.QueryRowContext(context.Background(), "SELECT value FROM ItemTable WHERE key = ?", cursorStateStatsigBootstrapKey).Scan(&raw); err != nil {
+		t.Fatalf("read bootstrap: %v", err)
+	}
+	return raw
+}
+
+func assertCursorStatsigGateValueForTest(t *testing.T, raw []byte, name string, want bool) {
+	t.Helper()
+	var payload struct {
+		FeatureGates map[string]struct {
+			Value bool `json:"value"`
+		} `json:"feature_gates"`
+	}
+	if err := json.Unmarshal(raw, &payload); err != nil {
+		t.Fatalf("decode bootstrap: %v", err)
+	}
+	gate, ok := payload.FeatureGates[name]
+	if !ok {
+		t.Fatalf("missing gate %q", name)
+	}
+	if gate.Value != want {
+		t.Fatalf("gate %q value=%t, want %t", name, gate.Value, want)
+	}
+}