feat: output_format: text でcommand出力をテキストとして扱う機能を追加

PreToolUse, PostToolUse, SessionStart, SessionEnd で
output_format: text を設定すると、commandの非JSON出力を正常扱いする。

- PreToolUse: テキスト出力を permissionDecisionReason に格納、allow扱い
- PostToolUse: テキスト出力を additionalContext に格納、allow扱い
- SessionStart: テキスト出力を additionalContext に格納
- SessionEnd: テキスト出力を systemMessage に格納

非ゼロ終了コード時は既存のfail-safe挙動を維持。
未設定時は既存のJSON出力期待挙動を維持（後方互換性あり）。

Author: syou6162

executor.go

@@ -698,6 +698,15 @@ func (e *ActionExecutor) ExecuteSessionStartAction(action Action, input *Session
 			}, nil
 		}
 
+		// output_format: text - treat command output as plain text (no JSON parsing)
+		if action.OutputFormat != nil && *action.OutputFormat == "text" {
+			return &ActionOutput{
+				Continue:          true,
+				HookEventName:     "SessionStart",
+				AdditionalContext: strings.TrimSpace(stdout),
+			}, nil
+		}
+
 		// Parse JSON output
 		var cmdOutput SessionStartOutput
 		if err := json.Unmarshal([]byte(stdout), &cmdOutput); err != nil {
@@ -966,6 +975,14 @@ func (e *ActionExecutor) ExecuteSessionEndAction(action Action, input *SessionEn
 			}, nil
 		}
 
+		// output_format: text - treat command output as plain text (no JSON parsing)
+		if action.OutputFormat != nil && *action.OutputFormat == "text" {
+			return &ActionOutput{
+				Continue:      true,
+				SystemMessage: strings.TrimSpace(stdout),
+			}, nil
+		}
+
 		// Parse JSON output (SessionEndOutput has Common JSON Fields only)
 		var cmdOutput SessionEndOutput
 		if err := json.Unmarshal([]byte(stdout), &cmdOutput); err != nil {

executor_test.go

@@ -2875,7 +2875,7 @@ func TestExecuteSessionStartAction_OutputFormatText(t *testing.T) {
 			stderr:            "command error",
 			exitCode:          1,
 			wantContinue:      false,
-			wantHookEventName: "SessionStart",
+			wantHookEventName: "", // non-zero exit uses existing behavior (HookEventName not set)
 		},
 	}
 

executor_tool_permission.go

@@ -37,6 +37,16 @@ func (e *ActionExecutor) ExecutePreToolUseAction(action Action, input *PreToolUs
 			return nil, nil
 		}
 
+		// output_format: text - treat command output as plain text (no JSON parsing)
+		if action.OutputFormat != nil && *action.OutputFormat == "text" {
+			return &ActionOutput{
+				Continue:                 true,
+				PermissionDecision:       "allow",
+				PermissionDecisionReason: strings.TrimSpace(stdout),
+				HookEventName:            "PreToolUse",
+			}, nil
+		}
+
 		// Parse JSON output
 		var cmdOutput PreToolUseOutput
 		if err := json.Unmarshal([]byte(stdout), &cmdOutput); err != nil {
@@ -244,6 +254,16 @@ func (e *ActionExecutor) ExecutePostToolUseAction(action Action, input *PostTool
 			}, nil
 		}
 
+		// output_format: text - treat command output as plain text (no JSON parsing)
+		if action.OutputFormat != nil && *action.OutputFormat == "text" {
+			return &ActionOutput{
+				Continue:          true,
+				Decision:          "", // Allow tool result
+				AdditionalContext: strings.TrimSpace(stdout),
+				HookEventName:     "PostToolUse",
+			}, nil
+		}
+
 		// Parse JSON output (PostToolUseOutput with hookSpecificOutput)
 		var cmdOutput PostToolUseOutput
 		if err := json.Unmarshal([]byte(stdout), &cmdOutput); err != nil {