perf(command-loader): parallelize directory scanning

- Add async loadCommandsFromDirAsync using fs.promises API
- Add 4 async load functions for user/project/global/project-opencode commands
- Add loadAllCommandsAsync with Promise.all parallelization
- Sync versions preserved for backward compatibility

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

src/features/claude-code-command-loader/loader.ts

@@ -1,4 +1,5 @@
 import { existsSync, readdirSync, readFileSync, realpathSync, type Dirent } from "fs"
+import { promises as fsPromises } from "fs"
 import { join, basename } from "path"
 import { parseFrontmatter } from "../../shared/frontmatter"
 import { sanitizeModelField } from "../../shared/model-sanitizer"
@@ -129,3 +130,130 @@ export function loadOpencodeProjectCommands(): Record<string, CommandDefinition>
   const commands = loadCommandsFromDir(opencodeProjectDir, "opencode-project")
   return commandsToRecord(commands)
 }
+
+async function loadCommandsFromDirAsync(
+  commandsDir: string,
+  scope: CommandScope,
+  visited: Set<string> = new Set(),
+  prefix: string = ""
+): Promise<LoadedCommand[]> {
+  try {
+    await fsPromises.access(commandsDir)
+  } catch {
+    return []
+  }
+
+  let realPath: string
+  try {
+    realPath = await fsPromises.realpath(commandsDir)
+  } catch (error) {
+    log(`Failed to resolve command directory: ${commandsDir}`, error)
+    return []
+  }
+
+  if (visited.has(realPath)) {
+    return []
+  }
+  visited.add(realPath)
+
+  let entries: Dirent[]
+  try {
+    entries = await fsPromises.readdir(commandsDir, { withFileTypes: true })
+  } catch (error) {
+    log(`Failed to read command directory: ${commandsDir}`, error)
+    return []
+  }
+
+  const commands: LoadedCommand[] = []
+
+  for (const entry of entries) {
+    if (entry.isDirectory()) {
+      if (entry.name.startsWith(".")) continue
+      const subDirPath = join(commandsDir, entry.name)
+      const subPrefix = prefix ? `${prefix}:${entry.name}` : entry.name
+      const subCommands = await loadCommandsFromDirAsync(subDirPath, scope, visited, subPrefix)
+      commands.push(...subCommands)
+      continue
+    }
+
+    if (!isMarkdownFile(entry)) continue
+
+    const commandPath = join(commandsDir, entry.name)
+    const baseCommandName = basename(entry.name, ".md")
+    const commandName = prefix ? `${prefix}:${baseCommandName}` : baseCommandName
+
+    try {
+      const content = await fsPromises.readFile(commandPath, "utf-8")
+      const { data, body } = parseFrontmatter<CommandFrontmatter>(content)
+
+      const wrappedTemplate = `<command-instruction>
+ ${body.trim()}
+ </command-instruction>
+
+ <user-request>
+ $ARGUMENTS
+ </user-request>`
+
+      const formattedDescription = `(${scope}) ${data.description || ""}`
+
+      const isOpencodeSource = scope === "opencode" || scope === "opencode-project"
+      const definition: CommandDefinition = {
+        name: commandName,
+        description: formattedDescription,
+        template: wrappedTemplate,
+        agent: data.agent,
+        model: sanitizeModelField(data.model, isOpencodeSource ? "opencode" : "claude-code"),
+        subtask: data.subtask,
+        argumentHint: data["argument-hint"],
+        handoffs: data.handoffs,
+      }
+
+      commands.push({
+        name: commandName,
+        path: commandPath,
+        definition,
+        scope,
+      })
+    } catch (error) {
+      log(`Failed to parse command: ${commandPath}`, error)
+      continue
+    }
+  }
+
+  return commands
+}
+
+export async function loadUserCommandsAsync(): Promise<Record<string, CommandDefinition>> {
+  const userCommandsDir = join(getClaudeConfigDir(), "commands")
+  const commands = await loadCommandsFromDirAsync(userCommandsDir, "user")
+  return commandsToRecord(commands)
+}
+
+export async function loadProjectCommandsAsync(): Promise<Record<string, CommandDefinition>> {
+  const projectCommandsDir = join(process.cwd(), ".claude", "commands")
+  const commands = await loadCommandsFromDirAsync(projectCommandsDir, "project")
+  return commandsToRecord(commands)
+}
+
+export async function loadOpencodeGlobalCommandsAsync(): Promise<Record<string, CommandDefinition>> {
+  const { homedir } = require("os")
+  const opencodeCommandsDir = join(homedir(), ".config", "opencode", "command")
+  const commands = await loadCommandsFromDirAsync(opencodeCommandsDir, "opencode")
+  return commandsToRecord(commands)
+}
+
+export async function loadOpencodeProjectCommandsAsync(): Promise<Record<string, CommandDefinition>> {
+  const opencodeProjectDir = join(process.cwd(), ".opencode", "command")
+  const commands = await loadCommandsFromDirAsync(opencodeProjectDir, "opencode-project")
+  return commandsToRecord(commands)
+}
+
+export async function loadAllCommandsAsync(): Promise<Record<string, CommandDefinition>> {
+  const [user, project, global, projectOpencode] = await Promise.all([
+    loadUserCommandsAsync(),
+    loadProjectCommandsAsync(),
+    loadOpencodeGlobalCommandsAsync(),
+    loadOpencodeProjectCommandsAsync(),
+  ])
+  return { ...projectOpencode, ...global, ...project, ...user }
+}