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/explore.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 = "opencode/grok-code"
 
@@ -24,14 +25,19 @@ export const EXPLORE_PROMPT_METADATA: AgentPromptMetadata = {
 }
 
 export function createExploreAgent(model: string = DEFAULT_MODEL): AgentConfig {
+  const restrictions = createAgentToolRestrictions([
+    "write",
+    "edit",
+    "background_task",
+  ])
+
   return {
     description:
       'Contextual grep for codebases. Answers "Where is X?", "Which file has Y?", "Find the code that does Z". Fire multiple in parallel for broad searches. Specify thoroughness: "quick" for basic, "medium" for moderate, "very thorough" for comprehensive analysis.',
     mode: "subagent" as const,
     model,
     temperature: 0.1,
-    tools: { write: false, background_task: false },
-    permission: { edit: "deny" as const },
+    ...restrictions,
     prompt: `You are a codebase search specialist. Your job: find files and code, return actionable results.
 
 ## Your Mission