feat: support use . to set current dir as default project and auto-detect project from cwd

resolveProjectDir now walks up from cwd to find .fba.json, so commands
work from any subdirectory inside a project.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yuWorm

src/commands/use.ts

@@ -1,12 +1,35 @@
 // use.ts — 切换默认项目
+import { resolve } from 'path'
 import * as clack from '@clack/prompts'
 import chalk from 'chalk'
-import { readGlobalConfig, setCurrentProject } from '../lib/config.js'
+import { readGlobalConfig, setCurrentProject, findProjectDirUpwards } from '../lib/config.js'
 import { t } from '../lib/i18n.js'
 
-export async function useAction() {
+export async function useAction(dir?: string) {
   const config = readGlobalConfig()
 
+  // fba use . 或 fba use <dir>：从指定目录向上查找项目
+  if (dir) {
+    const startDir = resolve(dir)
+    const projectDir = findProjectDirUpwards(startDir)
+    if (!projectDir) {
+      console.log(chalk.red(t('useNotFbaProject')))
+      return
+    }
+
+    const entry = config.projects.find(p => p.path === projectDir)
+    if (!entry) {
+      console.log(chalk.red(t('useNotRegistered')))
+      console.log(chalk.dim(t('useHintAdd')))
+      return
+    }
+
+    setCurrentProject(projectDir)
+    console.log(chalk.green(`${t('projectSwitched')} ${entry.name}`))
+    return
+  }
+
+  // 交互式选择
   if (config.projects.length === 0) {
     console.log(chalk.dim(t('projectListEmpty')))
     return

src/index.ts

@@ -193,11 +193,11 @@ program
   })
 
 program
-  .command('use')
+  .command('use [dir]')
   .description(t('cmdUse'))
-  .action(async () => {
+  .action(async (dir?: string) => {
     const { useAction } = await import('./commands/use.js')
-    await useAction()
+    await useAction(dir)
   })
 
 program

src/lib/config.ts

@@ -1,6 +1,6 @@
 // config.ts — 全局 & 项目配置 CRUD
 import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'fs'
-import { join } from 'path'
+import { join, dirname, resolve, parse } from 'path'
 import { homedir } from 'os'
 import type { GlobalConfig, ProjectConfig, ProjectEntry } from '../types/config.js'
 import { DEFAULT_GLOBAL_CONFIG, DEFAULT_PROJECT_CONFIG } from '../types/config.js'
@@ -98,10 +98,27 @@ export function writeProjectConfig(projectDir: string, config: ProjectConfig): v
 // ─── 路径解析 ───
 
 /**
- * 解析项目目录：优先命令行 -p 参数，其次全局 current
+ * 从指定目录向上查找包含 .fba.json 的项目根目录
+ */
+export function findProjectDirUpwards(startDir?: string): string | null {
+  let dir = resolve(startDir ?? process.cwd())
+  const root = parse(dir).root
+  while (true) {
+    if (existsSync(join(dir, '.fba.json'))) return dir
+    const parent = dirname(dir)
+    if (parent === dir || parent === root) break
+    dir = parent
+  }
+  return null
+}
+
+/**
+ * 解析项目目录：优先命令行 -p 参数，其次 cwd 向上查找，最后全局 current
  */
 export function resolveProjectDir(cliProjectDir?: string): string | null {
   if (cliProjectDir) return cliProjectDir
+  const fromCwd = findProjectDirUpwards()
+  if (fromCwd) return fromCwd
   return getCurrentProjectPath()
 }
 

src/lib/i18n.ts

@@ -194,6 +194,11 @@ const messages = {
     projectListEmpty: "暂无已注册项目",
     goClipboard: "已复制到剪贴板！粘贴以导航：",
 
+    // Use
+    useNotFbaProject: "当前目录不是 FBA 项目（未找到 .fba.json）",
+    useNotRegistered: "该项目尚未注册到管理列表",
+    useHintAdd: '运行 "fba-cli add" 将项目添加到管理列表',
+
     // Errors & hints
     projectDirNotExist: "项目目录不存在",
     backendDirNotFound: "后端目录未找到",
@@ -497,6 +502,11 @@ const messages = {
     projectListEmpty: "No projects registered",
     goClipboard: "Copied to clipboard! Paste to navigate:",
 
+    // Use
+    useNotFbaProject: "Current directory is not an FBA project (.fba.json not found)",
+    useNotRegistered: "This project is not registered in the managed list",
+    useHintAdd: 'Run "fba-cli add" to add the project to the managed list',
+
     projectDirNotExist: "Project directory does not exist",
     backendDirNotFound: "Backend directory not found",
     frontendDirNotFound: "Frontend directory not found",