refactor(billing)!: 计费全部沉入插件，内核零 billing 代码；规则由插件自持

按维护者要求（issue #1 回复方向）：内核不处理任何 billing 特有逻辑；插件有完整
OS 权限，自己保存配置文件。据此不再保留任何"内核 ↔ billing 插件"的专用对接。

- `internal/billing`（Go 编译器 + 测试）：删除；
- `internal/core` 的 billing 接口/降级应用/规则加载：删除（含 `billingPath`）；
- `internal/gateway` 的 `/api/plugins/billing/rules` 端点与测试：删除；
- `config` 的 `BillingDSL/Profile/Rule/Token/Peak/LongContext` 与校验、
  `billing:`/`billing_file:` 配置段：删除。系统配置里不再有 billing 段。
内核只保留所有插件通用的能力：加载 .lua、插件状态持久化、插件目录
（`__llmsproxy_plugin_dir`）、`plugin.http` 路由、插件可用的 io/os。

- 规则文件移到**插件自己的目录**：`<plugin_dir>/billing.json`，由插件用 io 自己
  读写（tmp + rename 原子替换）；加载插件时自己读文件并编译；
- 规则以**源名** `source` 为键（`url:"*"` 仅表示全局模型价目表）：URL→源名映射
  属于内核配置，插件不为它和内核对接；编辑页在浏览器里取 `/api/sources` 选源名；
- 规则编辑 API 改为插件自己的 `/api/plugins/http/billing/rules`
  （GET/PUT/POST/DELETE，roles=admin），写盘也在插件内完成；
- 计费账目仍在插件状态文件（内核通用持久化）`<plugin_dir>/.billing.state.json`；
- `priceFor` 落地 profile 级 `default` 策略与显式 `mode=unpriced` 的优先级。

生产已迁移：`config.yaml` 的 `billing:` 规则转为 `plugins/billing.json`（按源名
重写），并从系统配置中移除；规则文件与系统配置从此各自独立保存。

- `internal/lua/billing_rules_test.go`：插件自写 billing.json 并重启恢复、
  free/subscription/token/通配符编译语义、1e6+1e6 token = 0.75 端到端、
  非法规则被拒且不覆盖旧文件、reasoning/long_context/peak；
- `internal/lua/billing_test.go`：profile default 策略三态 + 显式 unpriced 优先；
- `internal/lua/billing_ui_test.go`：规则编辑页仍挂在 billing 页内、列宽/列数守卫。

(cherry picked from commit 7941b4110a)

internal/lua/plugins/billing.lua

@@ -72,6 +72,397 @@ local DEFAULT_PRICES = {
 }
 plugin.prices = DEFAULT_PRICES
 
+<<<<<<< HEAD
+=======
+-- ===== 规则 → 价格表编译（全部在插件内） ==============================
+--
+-- billing 没有任何内核逻辑（issue #1 的方向）：规则文件、编译、计价、账目、
+-- 规则编辑页全部由本插件负责。内核既不知道 billing.json，也不知道
+-- free/token/subscription 这些语义 —— 它只做通用的"加载插件 / 持久化插件状态 /
+-- 提供通用 HTTP 与文件能力"。
+--
+-- 规则以**源名**（`source`）为键，而不是 URL：URL→源名的映射属于内核配置，
+-- 插件不该为了它去和内核对接；而编辑页跑在浏览器里，可以直接取 /api/sources
+-- 让运营选源名。`url: "*"` 只保留为"全局模型价目表"（模型维度本来就不分源）。
+local VALID_MODES = { free = true, token = true, subscription = true, unpriced = true }
+
+local function trim(v)
+  local s = tostring(v == nil and "" or v)
+  return (s:gsub("^%s+", ""):gsub("%s+$", ""))
+end
+
+-- USD per million → USD per token.
+local function usdPerM(v)
+  local n = tonumber(trim(v))
+  if n == nil then return nil, "not a number: \"" .. tostring(v) .. "\"" end
+  if n < 0 then return nil, "negative price: \"" .. tostring(v) .. "\"" end
+  return n / 1e6, nil
+end
+
+local function compilePeak(pk)
+  local win = {}
+  if type(pk.weekdays) == "table" and #pk.weekdays > 0 then
+    local days = {}
+    for i, d in ipairs(pk.weekdays) do days[i] = d end
+    win.days = days
+  end
+  if type(pk.hours) == "table" and #pk.hours > 0 then
+    local hours = {}
+    for i, h in ipairs(pk.hours) do hours[i] = { h[1], h[2] } end
+    win.hours = hours
+  end
+  local out = { multiplier = tonumber(pk.multiplier) or 1 }
+  if next(win) ~= nil then out.windows = { win } end
+  return out
+end
+
+local function longContextRate(lc, basePerToken)
+  local prompt = trim(lc.prompt)
+  local mult = tonumber(lc.multiplier) or 0
+  if prompt ~= "" then
+    local v, err = usdPerM(prompt)
+    if not v then return nil, err end
+    return v, nil
+  end
+  if mult > 0 then return basePerToken * mult, nil end
+  return nil, "needs either prompt or multiplier"
+end
+
+-- 一条规则作用于哪个源。`source` 是正式写法；`url` 若不是 "*"，仅在它恰好
+-- 等于源名时兼容（旧配置迁移用）。
+local function ruleSource(rule)
+  local src = trim(rule.source)
+  if src ~= "" then return src end
+  local u = trim(rule.url)
+  if u ~= "" and u ~= "*" then return u end
+  return nil
+end
+
+local function applyRule(prices, rule, srcName)
+  local mode = rule.mode
+  if mode == "free" or mode == "subscription" then
+    prices.sources[srcName] = { prompt = 0, completion = 0, per_request = 0 }
+    if mode == "subscription" then
+      if prices.subscriptions == nil then prices.subscriptions = {} end
+      local cur = trim(rule.currency)
+      if cur == "" then cur = "USD" end
+      prices.subscriptions[srcName] = { monthly = tonumber(rule.subscription) or 0, currency = cur }
+    end
+    return true
+  end
+  if mode == "unpriced" then
+    -- 刻意不写条目并显式记录：profile 的 default=free 也不能把它当"免费"。
+    prices.explicit_unpriced[srcName] = true
+    return true
+  end
+  if mode == "token" then
+    if type(rule.models) ~= "table" or next(rule.models) == nil then
+      return nil, string.format("token rule for %q requires at least one model",
+        tostring(rule.source or rule.url))
+    end
+    for modelID, t in pairs(rule.models) do
+      local prompt, perr = usdPerM(t.prompt)
+      if not prompt then return nil, string.format("model %q prompt: %s", tostring(modelID), perr) end
+      local completion, cerr = usdPerM(t.completion)
+      if not completion then return nil, string.format("model %q completion: %s", tostring(modelID), cerr) end
+      local entry = { prompt = prompt, completion = completion }
+      if t.cache_discount ~= nil then entry.cache_discount = tonumber(t.cache_discount) end
+      if trim(t.reasoning) ~= "" then
+        local rp, rerr = usdPerM(t.reasoning)
+        if not rp then return nil, string.format("model %q reasoning: %s", tostring(modelID), rerr) end
+        entry.reasoning_price = rp
+      end
+      if type(t.long_context) == "table" then
+        local above = tonumber(t.long_context.above) or 0
+        if above <= 0 then
+          return nil, string.format("model %q long_context: above must be > 0", tostring(modelID))
+        end
+        local rate, lerr = longContextRate(t.long_context, prompt)
+        if not rate then return nil, string.format("model %q long_context: %s", tostring(modelID), lerr) end
+        entry.long_context = { above = above, prompt = rate }
+      end
+      if type(rule.peak) == "table" then entry.peak = compilePeak(rule.peak) end
+      prices.models[modelID] = entry
+    end
+    -- token 规则**不写源条目**：未列价的模型进入 unpriced 统计（可见）。
+    return true
+  end
+  return nil, string.format("unknown mode %q", tostring(mode))
+end
+
+-- compileRules(profile) → { prices, warnings } 或 nil, err。
+-- 不接收源列表：规则以源名为键，编译器不需要知道网关上有哪些源。
+local function compileRules(profile)
+  if type(profile) ~= "table" then return nil, "no billing profile" end
+  local prices = {
+    currency = "USD",
+    default = { prompt = 0, completion = 0, per_request = 0 },
+    sources = {}, models = {}, keys = {}, explicit_unpriced = {},
+  }
+  if profile.default == "free" or profile.default == "unpriced" then
+    prices.default_mode = profile.default
+  end
+  local rules = type(profile.rules) == "table" and profile.rules or {}
+  for i = 1, #rules do
+    local c = trim(rules[i].currency)
+    if c ~= "" then prices.currency = c break end
+  end
+  local warnings = {}
+  for i = 1, #rules do
+    local rule = rules[i]
+    local url = trim(rule.url)
+    local src = ruleSource(rule)
+    if url == "*" then
+      local ok, err = applyRule(prices, rule, nil)
+      if not ok then return nil, err end
+    elseif src == nil then
+      warnings[#warnings + 1] = "rule " .. i .. " 既没有 source 也没有 url=\"*\""
+    else
+      local ok, err = applyRule(prices, rule, src)
+      if not ok then return nil, err end
+    end
+  end
+  return { prices = prices, warnings = warnings }
+end
+
+-- ===== 规则持久化：插件自己读写自己的配置文件 ========================
+--
+-- 规则文件放在**插件自己的目录**（内核通过通用的 __llmsproxy_plugin_dir 暴露，
+-- 任何插件都能用；内核不知道 billing 的存在）：`<plugin_dir>/billing.json`。
+-- 用 JSON 因为插件沙箱只有 json 库；用独立文件因为"保存系统配置"绝不该改动
+-- 价目表，反之亦然。
+plugin.rules = { active = "", profiles = {} }
+plugin.rules_path = ""
+
+local function defaultRulesPath()
+  local dir = rawget(_G, "__llmsproxy_plugin_dir")
+  if type(dir) ~= "string" or dir == "" then return "" end
+  return dir .. "/billing.json"
+end
+
+local function readRulesFile(path)
+  if path == "" then return nil end
+  local f = io.open(path, "r")
+  if f == nil then return nil end
+  local data = f:read("*a")
+  f:close()
+  if data == nil or data == "" then return nil end
+  local ok, dec = pcall(json.decode, data)
+  if not ok or type(dec) ~= "table" then
+    return nil, "规则文件不是合法 JSON: " .. tostring(path)
+  end
+  return dec
+end
+
+local function writeRulesFile(path, rules)
+  if path == "" then return nil, "插件目录不可用，无法保存规则文件" end
+  local ok, enc = pcall(json.encode, rules)
+  if not ok then return nil, "规则无法序列化" end
+  local tmp = path .. ".tmp"
+  local f, err = io.open(tmp, "w")
+  if f == nil then return nil, "无法写规则文件: " .. tostring(err) end
+  local wok, werr = f:write(enc)
+  f:close()
+  if not wok then os.remove(tmp) return nil, "写规则文件失败: " .. tostring(werr) end
+  local rok, rerr = os.rename(tmp, path)
+  if not rok then
+    os.remove(tmp)
+    return nil, "替换规则文件失败: " .. tostring(rerr)
+  end
+  return true
+end
+
+local function validateRulesShape(rules)
+  if type(rules) ~= "table" then return nil, "规则必须是对象" end
+  if rules.active ~= nil and type(rules.active) ~= "string" then return nil, "active 必须是字符串" end
+  local profiles = rules.profiles
+  if profiles == nil then profiles = {} rules.profiles = profiles end
+  if type(profiles) ~= "table" then return nil, "profiles 必须是数组" end
+  local seen = {}
+  for i, p in ipairs(profiles) do
+    if type(p) ~= "table" then return nil, "profiles[" .. i .. "] 必须是对象" end
+    local id = trim(p.id)
+    if id == "" then return nil, "profiles[" .. i .. "] 缺少 id" end
+    if seen[id] then return nil, "profile id 重复: " .. id end
+    seen[id] = true
+    if p.default ~= nil and p.default ~= "free" and p.default ~= "unpriced" then
+      return nil, "profile " .. id .. " 的 default 只能是 free 或 unpriced"
+    end
+    if p.rules ~= nil and type(p.rules) ~= "table" then
+      return nil, "profile " .. id .. " 的 rules 必须是数组"
+    end
+    for j, r in ipairs(p.rules or {}) do
+      if type(r) ~= "table" then return nil, "profile " .. id .. " 的 rules[" .. j .. "] 必须是对象" end
+      local mode = trim(r.mode)
+      if not VALID_MODES[mode] then
+        return nil, "profile " .. id .. " 的 rules[" .. j .. "] 的 mode 非法: " .. mode
+      end
+      local wildcard = trim(r.url) == "*"
+      if ruleSource(r) == nil and not wildcard then
+        return nil, "profile " .. id .. " 的 rules[" .. j .. "] 必须有 source（或 url=\"*\" 作全局模型价目）"
+      end
+      if mode == "token" and (type(r.models) ~= "table" or next(r.models) == nil) then
+        return nil, "profile " .. id .. " 的 token 规则缺少 models"
+      end
+    end
+  end
+  if rules.active ~= nil and rules.active ~= "" and not seen[rules.active] then
+    return nil, "active 指向不存在的 profile: " .. rules.active
+  end
+  return true
+end
+
+local function activeProfile(rules)
+  local profile = nil
+  for _, p in ipairs(rules.profiles or {}) do
+    if rules.active ~= nil and rules.active ~= "" and p.id == rules.active then
+      profile = p
+      break
+    end
+  end
+  if profile == nil then profile = (rules.profiles or {})[1] end
+  return profile
+end
+
+-- applyRules：用给定规则重编译并注入 plugin.prices。启动、保存、切方案都走它。
+local function applyRules(rules)
+  local res, err = compileRules(activeProfile(rules) or {})
+  if not res then return nil, tostring(err) end
+  plugin.prices = res.prices
+  return res
+end
+
+-- 启动即加载：插件被内核加载时就自己读规则文件并编译 —— 内核不需要调用任何
+-- billing 专用接口，它只知道"加载插件"。
+plugin.rules_path = defaultRulesPath()
+do
+  local loaded, lerr = readRulesFile(plugin.rules_path)
+  if lerr then
+    plugin.load_error = lerr
+  elseif loaded ~= nil then
+    plugin.rules = loaded
+  end
+  local res, err = applyRules(plugin.rules)
+  if not res then plugin.load_error = tostring(err) end
+end
+
+-- ---- 规则编辑器的 HTTP 面（挂在插件自己的 /api/plugins/http/billing/ 下）----
+-- 规则属于插件，写盘也在插件内完成；内核没有 billing 端点。
+function plugin.__http_rules_get(req)
+  local out = { billing = plugin.rules, warnings = {} }
+  local profile = activeProfile(plugin.rules or {})
+  if profile then out.active = profile.id end
+  local res = profile and compileRules(profile)
+  if res and res.warnings then out.warnings = res.warnings end
+  if plugin.load_error then out.error = plugin.load_error end
+  return { status = 200, json = out }
+end
+
+function plugin.__http_rules_put(req)
+  local body = (req and (req.json or req))
+  if type(body) ~= "table" then
+    return { status = 400, json = { error = "请求体必须是 JSON 对象" } }
+  end
+  local rules = body.billing or body
+  local ok, verr = validateRulesShape(rules)
+  if not ok then return { status = 400, json = { error = verr } } end
+  local res, cerr = applyRules(rules)
+  if not res then return { status = 400, json = { error = tostring(cerr) } } end
+  local wok, werr = writeRulesFile(plugin.rules_path, rules)
+  if not wok then return { status = 500, json = { error = werr } } end
+  plugin.rules = rules
+  return { status = 200, json = { ok = true, billing = rules, warnings = res.warnings } }
+end
+
+function plugin.__http_rules_add(req)
+  local body = (req and (req.json or req)) or {}
+  local copy = json.decode(json.encode(plugin.rules or { active = "", profiles = {} }))
+  local target = nil
+  for _, p in ipairs(copy.profiles or {}) do
+    if body.profile == nil or body.profile == "" or p.id == body.profile then target = p break end
+  end
+  if target == nil then
+    return { status = 400, json = { error = "没有该方案: " .. tostring(body.profile) } }
+  end
+  local rule = body.rule
+  if type(rule) ~= "table" then return { status = 400, json = { error = "缺少 rule" } } end
+  local key = ruleSource(rule)
+  if key == nil then return { status = 400, json = { error = "规则必须有 source" } } end
+  target.rules = target.rules or {}
+  local replaced = false
+  for i, r in ipairs(target.rules) do
+    if ruleSource(r) == key and trim(r.url) == trim(rule.url) then
+      target.rules[i] = rule replaced = true break
+    end
+  end
+  if not replaced then target.rules[#target.rules + 1] = rule end
+  local ok, verr = validateRulesShape(copy)
+  if not ok then return { status = 400, json = { error = verr } } end
+  local res, cerr = applyRules(copy)
+  if not res then return { status = 400, json = { error = tostring(cerr) } } end
+  local wok, werr = writeRulesFile(plugin.rules_path, copy)
+  if not wok then return { status = 500, json = { error = werr } } end
+  plugin.rules = copy
+  return { status = 200, json = { ok = true, billing = copy } }
+end
+
+function plugin.__http_rules_delete(req)
+  local body = (req and (req.json or req)) or {}
+  local copy = json.decode(json.encode(plugin.rules or { active = "", profiles = {} }))
+  local target = nil
+  for _, p in ipairs(copy.profiles or {}) do
+    if body.profile == nil or body.profile == "" or p.id == body.profile then target = p break end
+  end
+  if target == nil then
+    return { status = 400, json = { error = "没有该方案: " .. tostring(body.profile) } }
+  end
+  local out = {}
+  local found = false
+  for _, r in ipairs(target.rules or {}) do
+    if ruleSource(r) == body.source or trim(r.url) == trim(body.url) then
+      found = true
+    else
+      out[#out + 1] = r
+    end
+  end
+  if not found then return { status = 404, json = { error = "没有该规则" } } end
+  target.rules = out
+  local ok, verr = validateRulesShape(copy)
+  if not ok then return { status = 400, json = { error = verr } } end
+  local res, cerr = applyRules(copy)
+  if not res then return { status = 400, json = { error = tostring(cerr) } } end
+  local wok, werr = writeRulesFile(plugin.rules_path, copy)
+  if not wok then return { status = 500, json = { error = werr } } end
+  plugin.rules = copy
+  return { status = 200, json = { ok = true, billing = copy } }
+end
+
+-- 直调导出（/api/plugins/billing/call/<fn>）：返回纯 JSON（不带 HTTP 状态壳），
+-- 便于运维/测试与插件自己的 HTTP 路由共用同一套实现。
+local function unwrap(res)
+  if type(res) == "table" and res.json ~= nil then return res.json end
+  return res
+end
+function plugin.rules_get(args) return unwrap(plugin.__http_rules_get({ json = args or {} })) end
+function plugin.rules_put(args) return unwrap(plugin.__http_rules_put({ json = args or {} })) end
+function plugin.rules_add(args) return unwrap(plugin.__http_rules_add({ json = args or {} })) end
+function plugin.rules_delete(args) return unwrap(plugin.__http_rules_delete({ json = args or {} })) end
+
+plugin.http = {
+  { path = "billing/rules", method = "GET", handler = "__http_rules_get",
+    roles = { "admin" }, description = "计费规则读取" },
+  { path = "billing/rules", method = "PUT", handler = "__http_rules_put",
+    roles = { "admin" }, description = "替换整份计费规则（插件自己写盘）" },
+  { path = "billing/rules", method = "POST", handler = "__http_rules_add",
+    roles = { "admin" }, description = "新增/替换一条计费规则" },
+  { path = "billing/rules", method = "DELETE", handler = "__http_rules_delete",
+    roles = { "admin" }, description = "删除一条计费规则" },
+}
+
+-- 测试/运维直调导出（/api/plugins/billing/call/...）；不是内核接口。
+plugin.exports = { "rules_get", "rules_put", "rules_add", "rules_delete" }
+
+>>>>>>> 7941b41 (refactor(billing)!: 计费全部沉入插件，内核零 billing 代码；规则由插件自持)
 -- Default prompt-cache discount. 0.1 = a cache read costs a tenth of a fresh
 -- token, which is what DeepSeek/Qwen/Kimi and most others charge. It can be
 -- overridden per price entry (prices.models.<m>.cache_discount) or globally by
@@ -236,6 +627,19 @@ local function priceFor(payload)
     if kp.cache_discount ~= nil then out.cache_discount = kp.cache_discount end
     if kp.peak ~= nil then out.peak = kp.peak end
   end
+<<<<<<< HEAD
+=======
+
+  -- profile 级 default 策略（编译期写入 prices.default_mode）在这里落地：
+  -- `free` = 运营声明"没有单独规则的源一律免费" ⇒ 计为已定价（不进 unpriced 统计）；
+  -- 但显式 mode=unpriced 的源必须仍计入，否则"只统计不收费"的声明失效。
+  if not out.priced and p.default_mode == "free" then
+    local explicit = p.explicit_unpriced
+    if not (type(explicit) == "table" and payload.source and explicit[payload.source]) then
+      out.priced = true
+    end
+  end
+>>>>>>> 7941b41 (refactor(billing)!: 计费全部沉入插件，内核零 billing 代码；规则由插件自持)
   return out
 end
 
@@ -1054,12 +1458,12 @@ plugin.ui = {
 })();
 
 (function () {
-  var API = "/api/plugins/billing/rules";
+  var API = "/api/plugins/http/billing/rules";
   var STR = {
     en: {
       title: "Billing rules", profile: "Profile", newProfile: "New profile",
       addRule: "Add rule", delRule: "Delete", exportYaml: "Export YAML",
-      url: "Source URL", mode: "Mode", prompt: "Prompt $/M",
+      source: "Source", mode: "Mode", prompt: "Prompt $/M",
       completion: "Completion $/M", currency: "Currency",
       monthly: "Monthly fee", peakMult: "Peak multiplier",
       peakHours: "Peak hours (UTC)", peakDays: "Peak days (UTC 1=Mon)",
@@ -1071,11 +1475,11 @@ plugin.ui = {
       lcHint: "Long-context step: tokens PAST the threshold cost more. Leave all three blank for one flat rate.",      reasoningHint: "Thinking tokens are billed as output unless you set a different rate here.",      mFree: "free", mToken: "token", mSub: "subscription", mUnpriced: "unpriced",
       noProfile: "No profile yet — create one to start pricing.",
       noRules: "No rules in this profile",
-      warnNoSource: "matches no configured source",
+      warnNoSource: "no such source on this gateway",
       active: "ACTIVE", setActive: "Set active",
       saving: "saving…", saved: "Saved", rejected: "Rejected", save: "Save",
       newProfileId: "New profile id",
-      needUrl: "a rule needs a URL", needPrices: "every model needs both prices",
+      needUrl: "a rule needs a source name (or url '*' for a global model catalogue)", needPrices: "every model needs both prices",
       badPeakHours: "peak hours look like 1-4,6-10 (UTC, 0-23)",
       badPeakDays: "peak days are UTC weekday numbers 0-6",
       peakNeedsMult: "peak hours need a multiplier",
@@ -1085,7 +1489,7 @@ plugin.ui = {
     zh: {
       title: "计费规则", profile: "方案", newProfile: "新建方案",
       addRule: "新增规则", delRule: "删除", exportYaml: "导出 YAML",
-      url: "源 URL", mode: "计费模式", prompt: "输入 $/M",
+      source: "源（source 名）", mode: "计费模式", prompt: "输入 $/M",
       completion: "输出 $/M", currency: "币种",
       monthly: "月费", peakMult: "峰段倍数",
       peakHours: "峰段小时 (UTC)", peakDays: "峰段星期 (UTC 1=周一)",
@@ -1098,11 +1502,11 @@ plugin.ui = {
       mSub: "subscription 订阅", mUnpriced: "unpriced 只统计",
       noProfile: "还没有方案 —— 新建一个开始定价。",
       noRules: "该方案暂无规则",
-      warnNoSource: "匹配不到已配置的源",
+      warnNoSource: "网关上没有这个源",
       active: "生效中", setActive: "设为生效",
       saving: "保存中…", saved: "已保存", rejected: "被拒绝", save: "保存",
       newProfileId: "新方案 id",
-      needUrl: "规则必须有 URL",
+      needUrl: "规则必须有源名（或 url '*' 作全局模型价目）",
       needPrices: "每个模型都要填输入和输出价格",
       badPeakHours: "峰段小时应形如 1-4,6-10（UTC，0-23）",
       badPeakDays: "峰段星期应为 UTC 星期编号 0-6",
@@ -1220,7 +1624,8 @@ plugin.ui = {
   }
 
   function ruleRow(rule, known, T) {
-    var unknown = rule.url !== "*" && known.indexOf(rule.url) < 0;
+    var src = rule.source || (rule.url !== "*" ? rule.url : "");
+    var unknown = src !== "" && src !== "*" && known.indexOf(src) < 0;
     var opts = [["free", T.mFree], ["token", T.mToken], ["subscription", T.mSub], ["unpriced", T.mUnpriced]]
       .map(function (o) {
         return "<option value='" + o[0] + "'" + (rule.mode === o[0] ? " selected" : "") + ">" + esc(o[1]) + "</option>";
@@ -1230,8 +1635,8 @@ plugin.ui = {
     // 的固有宽度会把列撑开：实测表格 986px 挤在 954px 容器里，最右侧的
     // 「删除」列被切掉 32px，按钮点不到；r-cur/r-sub 这些只有 style='width:74px'
     // 的输入框实测只有 40px 可用，几乎不能输入。
-    return "<tr class='br-rule' data-url='" + esc(rule.url || "") + "'>" +
-      "<td style='min-width:200px'><input class='r-url' value='" + esc(rule.url || "") + "' list='br-urls' style='width:100%;box-sizing:border-box'>" +
+    return "<tr class='br-rule' data-source='" + esc(src) + "'>" +
+      "<td style='min-width:200px'><input class='r-src' value='" + esc(src) + "' list='br-srcs' placeholder='source 名，或 * = 全局模型价目' style='width:100%;box-sizing:border-box'>" +
         (unknown ? "<div style='color:#e0a33e;font-size:11px'>&#9888; " + esc(T.warnNoSource) + "</div>" : "") +
       "</td>" +
       "<td style='width:88px'><select class='r-mode' style='width:100%;box-sizing:border-box;padding:2px;font-size:12px'>" + opts + "</select></td>" +
@@ -1248,10 +1653,11 @@ plugin.ui = {
 
   // ---- collecting one rule back out of the DOM ----------------------------
   function collectRule(tr, T) {
-    var url = tr.querySelector(".r-url").value.trim();
-    if (!url) throw new Error(T.needUrl);
+    var src = tr.querySelector(".r-src").value.trim();
+    if (!src) throw new Error(T.needUrl);
     var mode = tr.querySelector(".r-mode").value;
-    var out = { url: url, mode: mode };
+    var out = { source: src, mode: mode };
+    if (src === "*") { out.source = ""; out.url = "*"; }
     var cur = tr.querySelector(".r-cur").value.trim();
     if (cur) out.currency = cur;
     if (mode === "subscription") {
@@ -1401,7 +1807,8 @@ plugin.ui = {
       dsl.profiles.push({ id: id, rules: rules });
     });
     dsl.active = DATA && DATA.active ? DATA.active : (dsl.profiles[0] || {}).id;
-    return "billing:\n" + yamlValue(dsl, 1) + "\n";
+    // 规则现在是插件自持的 billing.json，导出就是同一个 JSON 结构。
+    return JSON.stringify(dsl, null, 2) + "\n";
   }
 
   // ---- render --------------------------------------------------------------
@@ -1419,7 +1826,7 @@ plugin.ui = {
     var dsl = (DATA && DATA.billing) || null;
     var profiles = (dsl && dsl.profiles) || [];
     var active = (DATA && DATA.active) || (profiles[0] && profiles[0].id) || "";
-    var known = (DATA && DATA.urls) || [];
+    var known = (DATA && DATA.sources) || [];
 
     var warn = "";
     if (DATA && DATA.warnings && DATA.warnings.length) {
@@ -1435,7 +1842,7 @@ plugin.ui = {
       return;
     }
 
-    var html = warn + "<datalist id='br-urls'>" + dl + "</datalist>";
+    var html = warn + "<datalist id='br-srcs'>" + dl + "</datalist>";
     profiles.forEach(function (p) {
       var rules = p.rules || [];
       html += "<div data-profile='" + esc(p.id) + "' style='margin:0 0 18px'>" +
@@ -1533,7 +1940,7 @@ plugin.ui = {
         }
         if (idx < 0) return;
         dsl.profiles[idx].rules = dsl.profiles[idx].rules.filter(function (r) {
-          return r.url !== tr.dataset.url;
+          return (r.source || r.url) !== tr.dataset.source;
         });
         save(dsl);
       };
@@ -1547,10 +1954,10 @@ plugin.ui = {
           if (dsl.profiles[i].id === b.dataset.pid) idx = i;
         }
         if (idx < 0) return;
-        // Seed with the first configured URL: an empty url row would fail
+        // Seed with the first configured source: an empty source row would fail
         // validation on save and the operator would not know why.
-        var first = ((DATA && DATA.urls) || [])[0] || "";
-        dsl.profiles[idx].rules.push({ url: first, mode: "free" });
+        var first = ((DATA && DATA.sources) || [])[0] || "*";
+        dsl.profiles[idx].rules.push({ source: first === "*" ? "" : first, url: first === "*" ? "*" : nil, mode: "free" });
         save(dsl);
       };
     });
@@ -1627,19 +2034,27 @@ plugin.ui = {
     p.innerHTML = "<button class='ghost small' id='br-dl'>" + esc(T.exportYaml) + " (.yaml)</button>";
     holder.appendChild(p);
     document.getElementById("br-dl").onclick = function () {
-      var blob = new Blob([text], { type: "text/yaml" });
+      var blob = new Blob([text], { type: "application/json" });
       var a = document.createElement("a");
       a.href = URL.createObjectURL(blob);
-      a.download = "billing-rules.yaml";
+      a.download = "billing.json";
       a.click();
       setTimeout(function () { URL.revokeObjectURL(a.href); }, 2000);
     };
   }
 
   function load() {
-    call("GET")
-      .then(function (j) {
-        DATA = { billing: j.billing || null, active: j.active, urls: j.urls || [], warnings: j.warnings || [] };
+    Promise.all([
+      call("GET"),
+      // 源名列表来自网关自己的 /api/sources（浏览器带管理员会话），插件不需要
+      // 为了它去和内核对接 —— 这正是"规则以源名为键"能做到零内核依赖的原因。
+      fetch("/api/sources", { credentials: "same-origin" })
+        .then(function (r) { return r.ok ? r.json() : { sources: [] }; })
+        .catch(function () { return { sources: [] }; }),
+    ]).then(function (res) {
+        var j = res[0], sj = res[1] || {};
+        var names = (sj.sources || []).map(function (s) { return s.name; }).filter(Boolean);
+        DATA = { billing: j.billing || null, active: j.active, sources: names, warnings: j.warnings || [] };
         render();
       })
       .catch(function (e) {