agent: add MaxSteps override in AgentCoreConfig and /maxsteps command

- AgentCoreConfig.MaxSteps: when non-zero, overrides the value loaded
  from the agent JSON (cfg.Env.maxSteps). Zero means "use the agent
  JSON value, or unlimited if absent". Callers (9p frontend, httpgw,
  CLI) can now inject a per-session limit at construction time without
  touching any agent config file.

- /maxsteps [n] command: shows the current limit (0 = unlimited) or
  sets it live during a session. Follows the same pattern as /model.
  Added to /help listing.

pkg/agent/commands.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"os/exec"
 	"slices"
+	"strconv"
 	"strings"
 
 	"ollie/pkg/config"
@@ -130,6 +131,28 @@ func (s *agent) handleCommand(ctx context.Context, input string, handler EventHa
 			handler(infoEvent("switched model to: " + args[0]))
 		},
 
+		"/maxsteps": func(args []string) {
+			if len(args) == 0 {
+				if s.cfg.MaxSteps == 0 {
+					handler(infoEvent("maxsteps: unlimited"))
+				} else {
+					handler(infoEvent(fmt.Sprintf("maxsteps: %d", s.cfg.MaxSteps)))
+				}
+				return
+			}
+			n, err := strconv.Atoi(args[0])
+			if err != nil || n < 0 {
+				handler(infoEvent("error: maxsteps requires a non-negative integer (0 = unlimited)"))
+				return
+			}
+			s.cfg.MaxSteps = n
+			if n == 0 {
+				handler(infoEvent("maxsteps: unlimited"))
+			} else {
+				handler(infoEvent(fmt.Sprintf("maxsteps: %d", n)))
+			}
+		},
+
 		"/agents": func(args []string) {
 			seen := make(map[string]bool)
 			found := false
@@ -190,6 +213,7 @@ func (s *agent) handleCommand(ctx context.Context, input string, handler EventHa
 			s.cfg.Tools = env.tools
 			s.cfg.Exec = env.exec
 			s.cfg.GenerationParams = env.genParams
+			s.cfg.MaxSteps = env.maxSteps
 			s.agentName = name
 			s.session = nil
 			s.sessionID = NewSessionID()
@@ -374,6 +398,7 @@ func (s *agent) handleCommand(ctx context.Context, input string, handler EventHa
 				"  /backend [type]  - show current backend, or switch to <type>",
 				"  /model [name]    - show current model, or switch to <name>",
 				"  /models          - list available models",
+				"  /maxsteps [n]    - show or set max tool-call steps (0 = unlimited)",
 				"  /skills          - list available skills",
 				"  /tools           - list available tools",
 				"  /cwd [path]      - show or change working directory",

pkg/agent/core.go

@@ -198,6 +198,9 @@ type AgentCoreConfig struct {
 	NewDispatcher func() tools.Dispatcher
 	NewBackend    func(string) (backend.Backend, error) // if nil, defaults to backend.NewWithName
 	Log           *olog.Logger                     // if nil, logging is disabled
+	// MaxSteps overrides the agent JSON maxSteps when non-zero.
+	// 0 means use the value from the agent config (or unlimited if absent).
+	MaxSteps      int
 }
 
 // agent is the Core implementation. It owns all agent and session state
@@ -323,6 +326,12 @@ func NewAgentCore(cfg AgentCoreConfig) Core {
 		GenerationParams:   cfg.Env.genParams,
 		MaxSteps:           cfg.Env.maxSteps,
 	}
+	// A non-zero MaxSteps in AgentCoreConfig takes precedence over the
+	// value loaded from the agent JSON, allowing callers to impose a
+	// per-session limit at construction time (e.g. via a CLI flag).
+	if cfg.MaxSteps > 0 {
+		run.MaxSteps = cfg.MaxSteps
+	}
 	if cfg.SessionID != "" {
 		os.MkdirAll(filepath.Join(ollieTmpDir(), cfg.SessionID), 0700) //nolint:errcheck
 	}