merge: resolve conflicts with main (workdir reuse)

Main added execenv.Reuse() for workdir reuse across tasks on the same
issue. Our branch removed Type/BranchName/gitRoot from Environment
(repos are now checked out on demand). Resolution: keep Reuse() but
simplify it to work with the new Environment struct (no workspace type
tracking). Keep the "reused" log field from main, drop removed fields.

server/internal/handler/agent.go

@@ -104,6 +104,7 @@ type AgentTaskResponse struct {
 	Repos          []RepoData     `json:"repos,omitempty"`
 	CreatedAt      string         `json:"created_at"`
 	PriorSessionID string         `json:"prior_session_id,omitempty"` // session ID from a previous task on same issue
+	PriorWorkDir   string         `json:"prior_work_dir,omitempty"`   // work_dir from a previous task on same issue
 }
 
 // TaskAgentData holds agent info included in claim responses so the daemon

server/internal/handler/daemon.go

@@ -244,6 +244,9 @@ func (h *Handler) ClaimTaskByRuntime(w http.ResponseWriter, r *http.Request) {
 		IssueID: task.IssueID,
 	}); err == nil && prior.SessionID.Valid {
 		resp.PriorSessionID = prior.SessionID.String
+		if prior.WorkDir.Valid {
+			resp.PriorWorkDir = prior.WorkDir.String
+		}
 	}
 
 	slog.Info("task claimed by runtime", "task_id", uuidToString(task.ID), "runtime_id", runtimeID, "agent_id", uuidToString(task.AgentID), "prior_session", resp.PriorSessionID)