api: make workspace root configurable instead of hardcoded /workspace

- Add workspaceRoot field (default "/workspace") to Server struct
- Add SetWorkspaceRoot method on Server
- Update handleListWorkspaces to use s.workspaceRoot
- Add WorkspaceRoot field to Config with default "/workspace"
- Wire cfg.WorkspaceRoot into server in serve.go
- Expose --workspace-root flag on the serve command
- Add TestListWorkspaces_UsesConfiguredRoot integration test

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

1 files changed, 9 insertions, 2 deletions

diff --git a/internal/api/server.go b/internal/api/server.go
index 1d87b3f..0868295 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -42,6 +42,7 @@ type Server struct {
 	validateCmdPath  string         // overrides claudeBinPath for validate; used in tests
 	scripts          ScriptRegistry // optional; maps endpoint name → script path
 	workDir          string         // working directory injected into elaborate system prompt
+	workspaceRoot    string         // root directory for listing workspaces; defaults to "/workspace"
 	notifier         notify.Notifier
 	apiToken         string         // if non-empty, required for WebSocket (and REST) connections
 	elaborateLimiter *ipRateLimiter // per-IP rate limiter for elaborate/validate endpoints
@@ -57,6 +58,11 @@ func (s *Server) SetNotifier(n notify.Notifier) {
 	s.notifier = n
 }
 
+// SetWorkspaceRoot configures the root directory used by handleListWorkspaces.
+func (s *Server) SetWorkspaceRoot(path string) {
+	s.workspaceRoot = path
+}
+
 func NewServer(store *storage.DB, pool *executor.Pool, logger *slog.Logger, claudeBinPath, geminiBinPath string) *Server {
 	wd, _ := os.Getwd()
 	s := &Server{
@@ -71,6 +77,7 @@ func NewServer(store *storage.DB, pool *executor.Pool, logger *slog.Logger, clau
 		claudeBinPath: claudeBinPath,
 		geminiBinPath: geminiBinPath,
 		workDir:       wd,
+		workspaceRoot: "/workspace",
 	}
 	s.routes()
 	return s
@@ -321,7 +328,7 @@ func (s *Server) handleListWorkspaces(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	entries, err := os.ReadDir("/workspace")
+	entries, err := os.ReadDir(s.workspaceRoot)
 	if err != nil {
 		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": "failed to list workspaces"})
 		return
@@ -329,7 +336,7 @@ func (s *Server) handleListWorkspaces(w http.ResponseWriter, r *http.Request) {
 	var dirs []string
 	for _, e := range entries {
 		if e.IsDir() {
-			dirs = append(dirs, "/workspace/"+e.Name())
+			dirs = append(dirs, s.workspaceRoot+"/"+e.Name())
 		}
 	}
 	writeJSON(w, http.StatusOK, dirs)