feat(config): allow runtime_fallback to be configured as boolean

Enable simple boolean configuration for runtime_fallback:
- "runtime_fallback": true - Enable with defaults
- "runtime_fallback": false - Disable
- "runtime_fallback": { ... } - Advanced object config (existing)

Updated schema, event handler, chat-message handler, and session hooks
to handle both boolean and object formats.

src/config/schema/oh-my-opencode-config.ts

@@ -44,7 +44,12 @@ export const OhMyOpenCodeConfigSchema = z.object({
   auto_update: z.boolean().optional(),
   skills: SkillsConfigSchema.optional(),
   ralph_loop: RalphLoopConfigSchema.optional(),
-  runtime_fallback: RuntimeFallbackConfigSchema.optional(),
+  /**
+   * Enable runtime fallback (default: true)
+   * Set to false to disable, or use object for advanced config:
+   * { "enabled": true, "retry_on_errors": [400, 429], "timeout_seconds": 30 }
+   */
+  runtime_fallback: z.union([z.boolean(), RuntimeFallbackConfigSchema]).optional(),
   background_task: BackgroundTaskConfigSchema.optional(),
   notification: NotificationConfigSchema.optional(),
   babysitting: BabysittingConfigSchema.optional(),

src/plugin/chat-message.ts

@@ -62,7 +62,9 @@ export function createChatMessageHandler(args: {
   const isRuntimeFallbackEnabled =
     hooks.runtimeFallback !== null &&
     hooks.runtimeFallback !== undefined &&
-    (pluginConfig.runtime_fallback?.enabled ?? true)
+    (typeof pluginConfig.runtime_fallback === "boolean"
+      ? pluginConfig.runtime_fallback
+      : (pluginConfig.runtime_fallback?.enabled ?? true))
 
   return async (
     input: ChatMessageInput,

src/plugin/event.ts

@@ -121,7 +121,9 @@ export function createEventHandler(args: {
   const isRuntimeFallbackEnabled =
     hooks.runtimeFallback !== null &&
     hooks.runtimeFallback !== undefined &&
-    (args.pluginConfig.runtime_fallback?.enabled ?? true)
+    (typeof args.pluginConfig.runtime_fallback === "boolean"
+      ? args.pluginConfig.runtime_fallback
+      : (args.pluginConfig.runtime_fallback?.enabled ?? true))
 
   // Avoid triggering multiple abort+continue cycles for the same failing assistant message.
   const lastHandledModelErrorMessageID = new Map<string, string>()

src/plugin/hooks/create-session-hooks.ts

@@ -245,10 +245,15 @@ export function createSessionHooks(args: {
     ? safeHook("anthropic-effort", () => createAnthropicEffortHook())
     : null
 
+  const runtimeFallbackConfig =
+    typeof pluginConfig.runtime_fallback === "boolean"
+      ? { enabled: pluginConfig.runtime_fallback }
+      : pluginConfig.runtime_fallback
+
   const runtimeFallback = isHookEnabled("runtime-fallback")
     ? safeHook("runtime-fallback", () =>
         createRuntimeFallbackHook(ctx, {
-          config: pluginConfig.runtime_fallback,
+          config: runtimeFallbackConfig,
           pluginConfig,
         }))
     : null