fix: surface actual session branch in frontend

backend/internal/httpd/apispec/openapi.yaml

@@ -1261,6 +1261,8 @@ components:
       properties:
         activity:
           $ref: '#/components/schemas/DomainActivity'
+        branch:
+          type: string
         createdAt:
           format: date-time
           type: string

backend/internal/httpd/controllers/dto.go

@@ -112,12 +112,14 @@ type CleanupSessionsQuery struct {
 }
 
 // SessionView is the session wire shape: the domain read model plus the
-// session's attributed pull requests in the curated SessionPRFacts shape. One
-// session can own many PRs (e.g. a stack), so prs is a list. The embedded
-// domain.Session.PRs field is json:"-"; this curated prs is what serializes.
+// display-safe branch name and the session's attributed pull requests in the
+// curated SessionPRFacts shape. One session can own many PRs (e.g. a stack), so
+// prs is a list. The embedded domain.Session.Metadata and domain.Session.PRs
+// fields are json:"-"; these curated fields are what serialize.
 type SessionView struct {
 	domain.Session
-	PRs []SessionPRFacts `json:"prs"`
+	Branch string           `json:"branch,omitempty"`
+	PRs    []SessionPRFacts `json:"prs"`
 }
 
 // ListSessionsResponse is the body of GET /api/v1/sessions.

backend/internal/httpd/controllers/sessions.go

@@ -427,7 +427,7 @@ func writeSessionPRError(w http.ResponseWriter, r *http.Request, err error) {
 }
 
 func sessionView(s domain.Session) SessionView {
-	return SessionView{Session: s, PRs: sessionPRFacts(s.PRs)}
+	return SessionView{Session: s, Branch: s.Metadata.Branch, PRs: sessionPRFacts(s.PRs)}
 }
 
 func sessionViews(sessions []domain.Session) []SessionView {

backend/internal/httpd/controllers/sessions_test.go

@@ -170,6 +170,9 @@ func TestSessionsRoutes_DefaultToStubsWithoutService(t *testing.T) {
 
 func TestSessionsAPI_ListSpawnGetAndActions(t *testing.T) {
 	svc := newFakeSessionService()
+	s := svc.sessions["ao-1"]
+	s.Metadata = domain.SessionMetadata{Branch: "qa/modal-worker", WorkspacePath: "/tmp/private-worktree", RuntimeHandleID: "runtime-1", Prompt: "private prompt"}
+	svc.sessions["ao-1"] = s
 	srv := newSessionTestServer(t, svc)
 
 	body, status, _ := doRequest(t, srv, "GET", "/api/v1/sessions?project=ao", "")
@@ -183,6 +186,22 @@ func TestSessionsAPI_ListSpawnGetAndActions(t *testing.T) {
 	if len(list.Sessions) != 1 || list.Sessions[0].ID != "ao-1" || list.Sessions[0].Status != string(domain.StatusIdle) || list.Sessions[0].TerminalHandleID != "ao-1/terminal_0" {
 		t.Fatalf("list = %#v", list)
 	}
+	if list.Sessions[0].Branch != "qa/modal-worker" {
+		t.Fatalf("branch = %q, want qa/modal-worker", list.Sessions[0].Branch)
+	}
+	var rawList struct {
+		Sessions []map[string]any `json:"sessions"`
+	}
+	mustJSON(t, body, &rawList)
+	if _, ok := rawList.Sessions[0]["metadata"]; ok {
+		t.Fatalf("list leaked metadata: %s", body)
+	}
+	if _, ok := rawList.Sessions[0]["workspacePath"]; ok {
+		t.Fatalf("list leaked workspacePath: %s", body)
+	}
+	if _, ok := rawList.Sessions[0]["prompt"]; ok {
+		t.Fatalf("list leaked prompt: %s", body)
+	}
 
 	body, status, _ = doRequest(t, srv, "POST", "/api/v1/sessions", `{"projectId":"ao","issueId":"ISS-1","kind":"worker","harness":"codex","prompt":"fix"}`)
 	if status != http.StatusCreated {
@@ -388,6 +407,7 @@ type sessionBody struct {
 	Kind             string `json:"kind"`
 	Harness          string `json:"harness"`
 	DisplayName      string `json:"displayName"`
+	Branch           string `json:"branch"`
 	Status           string `json:"status"`
 	TerminalHandleID string `json:"terminalHandleId"`
 }

frontend/src/api/schema.ts

@@ -446,6 +446,7 @@ export interface components {
         };
         ControllersSessionView: {
             activity: components["schemas"]["DomainActivity"];
+            branch?: string;
             /** Format: date-time */
             createdAt: string;
             displayName?: string;

frontend/src/renderer/hooks/useWorkspaceQuery.test.tsx

@@ -48,6 +48,7 @@ describe("useWorkspaceQuery", () => {
 							terminalHandleId: "term-1",
 							displayName: "fix-bug",
 							harness: "claude-code",
+							branch: "qa/modal-worker",
 							status: "mergeable",
 							isTerminated: false,
 							updatedAt: "2026-06-10T16:15:04Z",
@@ -81,12 +82,14 @@ describe("useWorkspaceQuery", () => {
 			terminalHandleId: "term-1",
 			title: "fix-bug",
 			provider: "claude-code",
+			branch: "qa/modal-worker",
 			status: "mergeable",
 		});
 		expect(workspace.sessions[1]).toMatchObject({
 			id: "sess-2",
 			title: "sess-2",
 			provider: "codex",
+			branch: "session/sess-2",
 			status: "working",
 		});
 	});

frontend/src/renderer/hooks/useWorkspaceQuery.ts

@@ -50,7 +50,7 @@ async function fetchWorkspaces(): Promise<WorkspaceSummary[]> {
 				title: session.displayName ?? session.issueId ?? session.id,
 				provider: toAgentProvider(session.harness),
 				kind: session.kind === "orchestrator" ? "orchestrator" : session.kind === "worker" ? "worker" : undefined,
-				branch: `session/${session.id}`,
+				branch: session.branch ?? `session/${session.id}`,
 				status: toSessionStatus(session.status, session.isTerminated),
 				createdAt: session.createdAt,
 				updatedAt: session.updatedAt,