fix: proper OpenCode v1.1.1 permission migration (#490)

* fix: implement proper version-aware permission format for OpenCode v1.1.1

- Rewrite permission-compat.ts with runtime version detection
- createAgentToolRestrictions() returns correct format per version
- v1.1.1+ uses permission format, older uses tools format
- Add migrateToolsToPermission/migratePermissionToTools helpers
- Update test suite for new API

🤖 Generated with assistance of OhMyOpenCode
https://github.com/code-yeongyu/oh-my-opencode

* fix: update all agents to use createAgentToolRestrictions()

- Replace hardcoded tools: { X: false } format with version-aware utility
- All agents now use createAgentToolRestrictions([...])
- Ensures compatibility with both old and new OpenCode versions

🤖 Generated with assistance of OhMyOpenCode
https://github.com/code-yeongyu/oh-my-opencode

* fix: add runtime migration for user agent configs in config-handler

Migrate tools/permission format in user/project/plugin agent configs
based on detected OpenCode version at load time.

🤖 Generated with [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/agents/document-writer.ts

@@ -1,5 +1,6 @@
 import type { AgentConfig } from "@opencode-ai/sdk"
 import type { AgentPromptMetadata } from "./types"
+import { createAgentToolRestrictions } from "../shared/permission-compat"
 
 const DEFAULT_MODEL = "google/gemini-3-flash-preview"
 
@@ -15,12 +16,14 @@ export const DOCUMENT_WRITER_PROMPT_METADATA: AgentPromptMetadata = {
 export function createDocumentWriterAgent(
   model: string = DEFAULT_MODEL
 ): AgentConfig {
+  const restrictions = createAgentToolRestrictions(["background_task"])
+
   return {
     description:
       "A technical writer who crafts clear, comprehensive documentation. Specializes in README files, API docs, architecture docs, and user guides. MUST BE USED when executing documentation tasks from ai-todo list plans.",
     mode: "subagent" as const,
     model,
-    tools: { background_task: false },
+    ...restrictions,
     prompt: `<role>
 You are a TECHNICAL WRITER with deep engineering background who transforms complex codebases into crystal-clear documentation. You have an innate ability to explain complex concepts simply while maintaining technical accuracy.