fix(zfc): move stuck detection thresholds to agent-controlled config

Per ZFC principle: 'Let agents decide thresholds. Stuck is a judgment call.'

Changes:
- Add health check threshold fields to RoleConfig (ping_timeout,
  consecutive_failures, kill_cooldown, stuck_threshold)
- Add LoadStuckConfig() to read thresholds from hq-deacon-role bead
- Update patrol_check.go to use configurable stuck threshold
- Defaults remain as fallbacks when no role bead config exists

Agents can now configure their stuck detection by adding fields to their
role bead, e.g.:
  ping_timeout: 45s
  consecutive_failures: 5
  kill_cooldown: 10m
  stuck_threshold: 2h

Fixes: hq-2355b

internal/deacon/stuck.go

@@ -8,13 +8,17 @@ import (
 	"os"
 	"path/filepath"
 	"time"
+
+	"github.com/steveyegge/gastown/internal/beads"
 )
 
 // Default parameters for stuck-session detection.
+// These are fallbacks when no role bead config exists.
+// Per ZFC: "Let agents decide thresholds. 'Stuck' is a judgment call."
 const (
-	DefaultPingTimeout        = 30 * time.Second // How long to wait for response
-	DefaultConsecutiveFailures = 3               // Failures before force-kill
-	DefaultCooldown           = 5 * time.Minute  // Minimum time between force-kills
+	DefaultPingTimeout         = 30 * time.Second // How long to wait for response
+	DefaultConsecutiveFailures = 3                // Failures before force-kill
+	DefaultCooldown            = 5 * time.Minute  // Minimum time between force-kills
 )
 
 // StuckConfig holds configurable parameters for stuck-session detection.
@@ -33,6 +37,37 @@ func DefaultStuckConfig() *StuckConfig {
 	}
 }
 
+// LoadStuckConfig loads stuck detection config from the Deacon's role bead.
+// Returns defaults if no role bead exists or if fields aren't configured.
+// Per ZFC: agents control their own thresholds via their role beads.
+func LoadStuckConfig(townRoot string) *StuckConfig {
+	config := DefaultStuckConfig()
+
+	// Load from hq-deacon-role bead
+	bd := beads.NewWithBeadsDir(townRoot, beads.ResolveBeadsDir(townRoot))
+	roleConfig, err := bd.GetRoleConfig(beads.RoleBeadIDTown("deacon"))
+	if err != nil || roleConfig == nil {
+		return config
+	}
+
+	// Override defaults with role bead values
+	if roleConfig.PingTimeout != "" {
+		if d, err := time.ParseDuration(roleConfig.PingTimeout); err == nil {
+			config.PingTimeout = d
+		}
+	}
+	if roleConfig.ConsecutiveFailures > 0 {
+		config.ConsecutiveFailures = roleConfig.ConsecutiveFailures
+	}
+	if roleConfig.KillCooldown != "" {
+		if d, err := time.ParseDuration(roleConfig.KillCooldown); err == nil {
+			config.Cooldown = d
+		}
+	}
+
+	return config
+}
+
 // AgentHealthState tracks the health check state for a single agent.
 type AgentHealthState struct {
 	// AgentID is the identifier (e.g., "gastown/polecats/max" or "deacon")