fix(core): load built-in skill asset at runtime

packages/core/src/markdown.d.ts

@@ -1,4 +0,0 @@
-declare module "*.md" {
-  const content: string
-  export default content
-}

packages/core/src/plugin/skill.ts

@@ -4,13 +4,13 @@ import { Effect } from "effect"
 import { PluginV2 } from "../plugin"
 import { AbsolutePath } from "../schema"
 import { SkillV2 } from "../skill"
-import CUSTOMIZE_OPENCODE_SKILL_BODY from "./skill/customize-opencode.md" with { type: "text" }
 
 export const Plugin = PluginV2.define({
   id: PluginV2.ID.make("skill"),
   effect: Effect.gen(function* () {
     const skill = yield* SkillV2.Service
     const transform = yield* skill.transform()
+    const content = yield* Effect.promise(() => Bun.file(new URL("./skill/customize-opencode.md", import.meta.url)).text())
 
     yield* transform((editor) => {
       editor.source(
@@ -21,7 +21,7 @@ export const Plugin = PluginV2.define({
             description:
               "Use ONLY when the user is editing or creating opencode's own configuration: opencode.json, opencode.jsonc, files under .opencode/, or files under ~/.config/opencode/. Also use when creating or fixing opencode agents, subagents, skills, plugins, MCP servers, or permission rules. Do not use for the user's own application code, or for any project that is not configuring opencode itself.",
             location: AbsolutePath.make("/builtin/customize-opencode.md"),
-            content: CUSTOMIZE_OPENCODE_SKILL_BODY,
+            content,
           }),
         }),
       )