feat: add OmO config with build agent hiding and startup toast

- Add configurable build agent hiding (omo_agent.disable_build)
- Add startup-toast hook to show version on OpenCode startup
- Fix auto-update-checker to respect version pinning

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

src/hooks/auto-update-checker/cache.ts

@@ -1,18 +1,47 @@
 import * as fs from "node:fs"
-import { VERSION_FILE } from "./constants"
+import * as path from "node:path"
+import { CACHE_DIR, PACKAGE_NAME } from "./constants"
 import { log } from "../../shared/logger"
 
-export function invalidateCache(): boolean {
+export function invalidatePackage(packageName: string = PACKAGE_NAME): boolean {
   try {
-    if (fs.existsSync(VERSION_FILE)) {
-      fs.unlinkSync(VERSION_FILE)
-      log(`[auto-update-checker] Cache invalidated: ${VERSION_FILE}`)
-      return true
+    const pkgDir = path.join(CACHE_DIR, "node_modules", packageName)
+    const pkgJsonPath = path.join(CACHE_DIR, "package.json")
+
+    let packageRemoved = false
+    let dependencyRemoved = false
+
+    if (fs.existsSync(pkgDir)) {
+      fs.rmSync(pkgDir, { recursive: true, force: true })
+      log(`[auto-update-checker] Package removed: ${pkgDir}`)
+      packageRemoved = true
     }
-    log("[auto-update-checker] Version file not found, nothing to invalidate")
-    return false
+
+    if (fs.existsSync(pkgJsonPath)) {
+      const content = fs.readFileSync(pkgJsonPath, "utf-8")
+      const pkgJson = JSON.parse(content)
+      if (pkgJson.dependencies?.[packageName]) {
+        delete pkgJson.dependencies[packageName]
+        fs.writeFileSync(pkgJsonPath, JSON.stringify(pkgJson, null, 2))
+        log(`[auto-update-checker] Dependency removed from package.json: ${packageName}`)
+        dependencyRemoved = true
+      }
+    }
+
+    if (!packageRemoved && !dependencyRemoved) {
+      log(`[auto-update-checker] Package not found, nothing to invalidate: ${packageName}`)
+      return false
+    }
+
+    return true
   } catch (err) {
-    log("[auto-update-checker] Failed to invalidate cache:", err)
+    log("[auto-update-checker] Failed to invalidate package:", err)
     return false
   }
 }
+
+/** @deprecated Use invalidatePackage instead - this nukes ALL plugins */
+export function invalidateCache(): boolean {
+  log("[auto-update-checker] WARNING: invalidateCache is deprecated, use invalidatePackage")
+  return invalidatePackage()
+}