fix(tools): make exec tool timeout configurable via config

Add TimeoutSeconds field to ExecConfig so the shell command execution
timeout can be configured instead of being hardcoded to 60s.

- Add TimeoutSeconds int field to ExecConfig in pkg/config/config.go
  with json/env tags (PICOCLAW_TOOLS_EXEC_TIMEOUT_SECONDS)
- Set default value of 60s in DefaultConfig() in pkg/config/defaults.go
- Read TimeoutSeconds from config in NewExecToolWithConfig() in
  pkg/tools/shell.go; falls back to 60s when value is 0 or unset

pkg/config/config.go

@@ -594,6 +594,7 @@ type ExecConfig struct {
 	EnableDenyPatterns  bool     `                                 env:"PICOCLAW_TOOLS_EXEC_ENABLE_DENY_PATTERNS"  json:"enable_deny_patterns"`
 	CustomDenyPatterns  []string `                                 env:"PICOCLAW_TOOLS_EXEC_CUSTOM_DENY_PATTERNS"  json:"custom_deny_patterns"`
 	CustomAllowPatterns []string `                                 env:"PICOCLAW_TOOLS_EXEC_CUSTOM_ALLOW_PATTERNS" json:"custom_allow_patterns"`
+	TimeoutSeconds      int      `                                 env:"PICOCLAW_TOOLS_EXEC_TIMEOUT_SECONDS"       json:"timeout_seconds"`       // 0 means use default (60s)
 }
 
 type SkillsToolsConfig struct {

pkg/config/defaults.go

@@ -386,6 +386,7 @@ func DefaultConfig() *Config {
 					Enabled: true,
 				},
 				EnableDenyPatterns: true,
+				TimeoutSeconds:     60,
 			},
 			Skills: SkillsToolsConfig{
 				ToolConfig: ToolConfig{

pkg/tools/shell.go

@@ -131,9 +131,14 @@ func NewExecToolWithConfig(workingDir string, restrict bool, config *config.Conf
 		denyPatterns = append(denyPatterns, defaultDenyPatterns...)
 	}
 
+	timeout := 60 * time.Second
+	if config != nil && config.Tools.Exec.TimeoutSeconds > 0 {
+		timeout = time.Duration(config.Tools.Exec.TimeoutSeconds) * time.Second
+	}
+
 	return &ExecTool{
 		workingDir:          workingDir,
-		timeout:             60 * time.Second,
+		timeout:             timeout,
 		denyPatterns:        denyPatterns,
 		allowPatterns:       nil,
 		customAllowPatterns: customAllowPatterns,