tui: parallelize skill downloads for faster loading

Refactored skill discovery to download skills in parallel instead of sequentially,

reducing load times when multiple skills need to be fetched from remote URLs.

Also updated AGENTS.md with guidance on using dev branch for diffs.

AGENTS.md

@@ -1,6 +1,7 @@
 - To regenerate the JavaScript SDK, run `./packages/sdk/js/script/build.ts`.
 - ALWAYS USE PARALLEL TOOLS WHEN APPLICABLE.
 - The default branch in this repo is `dev`.
+- Local `main` ref may not exist; use `dev` or `origin/dev` for diffs.
 - Prefer automation: execute requested actions without confirmation unless blocked by missing info or safety/irreversibility.
 
 ## Style Guide

packages/opencode/src/skill/discovery.ts

@@ -1,7 +1,7 @@
 import path from "path"
 import { mkdir } from "fs/promises"
 import { Log } from "../util/log"
-import { Global } from "@/global"
+import { Global } from "../global"
 
 export namespace Discovery {
   const log = Log.create({ service: "skill-discovery" })
@@ -20,60 +20,77 @@ export namespace Discovery {
 
   async function get(url: string, dest: string): Promise<boolean> {
     if (await Bun.file(dest).exists()) return true
-    try {
-      const response = await fetch(url)
-      if (!response.ok) {
-        log.error("failed to download", { url, status: response.status })
+    return fetch(url)
+      .then(async (response) => {
+        if (!response.ok) {
+          log.error("failed to download", { url, status: response.status })
+          return false
+        }
+        await Bun.write(dest, await response.text())
+        return true
+      })
+      .catch((err) => {
+        log.error("failed to download", { url, err })
         return false
-      }
-      const content = await response.text()
-      await Bun.write(dest, content)
-      return true
-    } catch (err) {
-      log.error("failed to download", { url, err })
-      return false
-    }
+      })
   }
 
   export async function pull(url: string): Promise<string[]> {
     const result: string[] = []
-    const indexUrl = new URL("index.json", url.endsWith("/") ? url : `${url}/`).href
-    const cacheDir = dir()
-
-    try {
-      log.info("fetching index", { url: indexUrl })
-      const response = await fetch(indexUrl)
-      if (!response.ok) {
-        log.error("failed to fetch index", { url: indexUrl, status: response.status })
-        return result
-      }
-
-      const index = (await response.json()) as Index
-      if (!index.skills || !Array.isArray(index.skills)) {
-        log.warn("invalid index format", { url: indexUrl })
-        return result
-      }
+    const base = url.endsWith("/") ? url : `${url}/`
+    const index = new URL("index.json", base).href
+    const cache = dir()
+    const host = base.slice(0, -1)
 
-      for (const skill of index.skills) {
-        if (!skill.name || !skill.files || !Array.isArray(skill.files)) {
-          log.warn("invalid skill entry", { url: indexUrl, skill })
-          continue
+    log.info("fetching index", { url: index })
+    const data = await fetch(index)
+      .then(async (response) => {
+        if (!response.ok) {
+          log.error("failed to fetch index", { url: index, status: response.status })
+          return undefined
         }
+        return response
+          .json()
+          .then((json) => json as Index)
+          .catch((err) => {
+            log.error("failed to parse index", { url: index, err })
+            return undefined
+          })
+      })
+      .catch((err) => {
+        log.error("failed to fetch index", { url: index, err })
+        return undefined
+      })
 
-        const skillDir = path.join(cacheDir, skill.name)
-        for (const file of skill.files) {
-          const fileUrl = new URL(file, `${url.replace(/\/$/, "")}/${skill.name}/`).href
-          const localPath = path.join(skillDir, file)
-          await mkdir(path.dirname(localPath), { recursive: true })
-          await get(fileUrl, localPath)
-        }
+    if (!data?.skills || !Array.isArray(data.skills)) {
+      log.warn("invalid index format", { url: index })
+      return result
+    }
 
-        const skillMd = path.join(skillDir, "SKILL.md")
-        if (await Bun.file(skillMd).exists()) result.push(skillDir)
+    const list = data.skills.filter((skill) => {
+      if (!skill?.name || !Array.isArray(skill.files)) {
+        log.warn("invalid skill entry", { url: index, skill })
+        return false
       }
-    } catch (err) {
-      log.error("failed to fetch from URL", { url, err })
-    }
+      return true
+    })
+
+    await Promise.all(
+      list.map(async (skill) => {
+        const root = path.join(cache, skill.name)
+        await Promise.all(
+          skill.files.map(async (file) => {
+            const link = new URL(file, `${host}/${skill.name}/`).href
+            const dest = path.join(root, file)
+            await mkdir(path.dirname(dest), { recursive: true })
+            await get(link, dest)
+          }),
+        )
+
+        const md = path.join(root, "SKILL.md")
+        if (await Bun.file(md).exists()) result.push(root)
+      }),
+    )
 
     return result
   }

packages/opencode/src/skill/skill.ts

@@ -153,9 +153,9 @@ export namespace Skill {
     }
 
     // Download and load skills from URLs
-    for (const skillUrl of config.skills?.urls ?? []) {
-      const downloadedDirs = await Discovery.pull(skillUrl)
-      for (const dir of downloadedDirs) {
+    for (const url of config.skills?.urls ?? []) {
+      const list = await Discovery.pull(url)
+      for (const dir of list) {
         dirs.add(dir)
         for await (const match of SKILL_GLOB.scan({
           cwd: dir,