配置页：订阅的增删改和立刻更新

写配置的纯逻辑在 shared/providers.ts。删除前 subscriptionReferences 同时查
直接 use 和经订阅副本（共用缓存文件 path）的间接引用，有被引用的就拦下并列出
策略组。订阅不允许改名：名字被 use: 和副本引用，同步所有引用不如删了重建。

页面还没挂进 App.vue 的导航，由集成者统一加。

shared/providers.test.ts

@@ -0,0 +1,161 @@
+import { describe, expect, it } from 'bun:test'
+import {
+  DEFAULT_INTERVAL,
+  addSubscription,
+  listSubscriptions,
+  providerNames,
+  removeSubscription,
+  subscriptionReferences,
+  updateSubscription,
+} from './providers.ts'
+import { applySetup, chainProviderName } from './inbound-groups.ts'
+import type { OutboundSetup } from './inbound-groups.ts'
+import type { ConfigObject } from '../vendor/config-editor/index.ts'
+
+const URL = 'http://127.0.0.1:3001/token/download/V2House'
+
+/** 一份带一个订阅的配置，形状仿照目标机器上那份。 */
+function base(): ConfigObject {
+  return {
+    'proxy-providers': {
+      subs: {
+        type: 'http',
+        url: URL,
+        path: './providers/subs.yaml',
+        interval: 86400,
+        'health-check': { enable: true, url: 'https://www.gstatic.com/generate_204', interval: 300 },
+      },
+    },
+    'proxy-groups': [{ name: 'PROXY', type: 'select', proxies: ['DIRECT'], use: ['subs'] }],
+  }
+}
+
+const chainedSetup: OutboundSetup = {
+  proxy: { sources: ['subs'], filter: null },
+  chain: { sources: ['subs'], filter: null },
+}
+
+describe('读出订阅列表', () => {
+  it('读出地址、间隔和健康检查', () => {
+    expect(listSubscriptions(base())).toEqual([
+      {
+        name: 'subs',
+        url: URL,
+        interval: 86400,
+        healthCheck: { url: 'https://www.gstatic.com/generate_204', interval: 300 },
+      },
+    ])
+  })
+
+  it('健康检查没写或没开都算未开启', () => {
+    const data = base()
+    const subs = (data['proxy-providers'] as ConfigObject).subs as ConfigObject
+    delete subs['health-check']
+    expect(listSubscriptions(data)[0]?.healthCheck).toBeNull()
+    subs['health-check'] = { enable: false, url: 'https://example.com', interval: 60 }
+    expect(listSubscriptions(data)[0]?.healthCheck).toBeNull()
+  })
+
+  it('不含 Patchbay 生成的订阅副本', () => {
+    const data = applySetup(
+      { ...base(), listeners: [{ name: 'test1', type: 'mixed', port: 7778 }] },
+      'test1',
+      chainedSetup,
+    )
+    expect(listSubscriptions(data).map((s) => s.name)).toEqual(['subs'])
+    // 副本还在，只是不列出来
+    expect(providerNames(data)).toContain(chainProviderName('test1', 'subs'))
+  })
+
+  it('没有 proxy-providers 段时是空列表', () => {
+    expect(listSubscriptions({ mode: 'rule' })).toEqual([])
+  })
+})
+
+describe('新增订阅', () => {
+  it('自动生成缓存路径和默认间隔', () => {
+    const next = addSubscription({}, 'subs2', URL)
+    expect(next['proxy-providers']).toEqual({
+      subs2: {
+        type: 'http',
+        url: URL,
+        path: './providers/subs2.yaml',
+        interval: DEFAULT_INTERVAL,
+      },
+    })
+  })
+
+  it('不动已有的订阅', () => {
+    const data = base()
+    const next = addSubscription(data, 'subs2', URL)
+    expect((next['proxy-providers'] as ConfigObject).subs).toEqual(
+      (data['proxy-providers'] as ConfigObject).subs,
+    )
+  })
+})
+
+describe('编辑订阅', () => {
+  it('只改地址和间隔，其余字段原样保留', () => {
+    const next = updateSubscription(base(), 'subs', 'http://example.com/new', 3600)
+    const entry = (next['proxy-providers'] as ConfigObject).subs as ConfigObject
+    expect(entry.url).toBe('http://example.com/new')
+    expect(entry.interval).toBe(3600)
+    expect(entry.path).toBe('./providers/subs.yaml')
+    expect(entry['health-check']).toEqual({
+      enable: true,
+      url: 'https://www.gstatic.com/generate_204',
+      interval: 300,
+    })
+  })
+
+  it('订阅不存在时不做改动', () => {
+    const data = base()
+    expect(updateSubscription(data, 'ghost', URL, 1)).toBe(data)
+  })
+})
+
+describe('删除订阅', () => {
+  it('从映射里去掉', () => {
+    const data = addSubscription(base(), 'subs2', URL)
+    const next = removeSubscription(data, 'subs2')
+    expect(providerNames(next)).toEqual(['subs'])
+  })
+
+  it('删到最后一个时整个键去掉，不留空映射', () => {
+    const next = removeSubscription(base(), 'subs')
+    expect('proxy-providers' in next).toBe(false)
+  })
+
+  it('订阅不存在时不做改动', () => {
+    const data = base()
+    expect(removeSubscription(data, 'ghost')).toBe(data)
+  })
+})
+
+describe('删除前的引用检查', () => {
+  it('找出 use 它的策略组', () => {
+    expect(subscriptionReferences(base(), 'subs')).toEqual(['PROXY'])
+  })
+
+  it('没人在用时是空列表', () => {
+    const data = base()
+    ;(data['proxy-groups'] as ConfigObject[])[0] = { name: 'PROXY', type: 'select', proxies: ['DIRECT'] }
+    expect(subscriptionReferences(data, 'subs')).toEqual([])
+  })
+
+  it('链式代理的专属组 use 的是副本，也算引用原订阅', () => {
+    const data = applySetup(
+      { ...base(), listeners: [{ name: 'test1', type: 'mixed', port: 7778 }] },
+      'test1',
+      chainedSetup,
+    )
+    const refs = subscriptionReferences(data, 'subs')
+    // 入口组直接 use 原订阅，三个专属组 use 副本，两边都要认出来
+    expect(refs).toContain('patchbay:test1 链式')
+    expect(refs).toContain('patchbay:test1')
+  })
+
+  it('订阅不存在时是空列表', () => {
+    expect(subscriptionReferences(base(), 'ghost')).toEqual([])
+  })
+})