feat(cc-config): add and remove MCP servers through the claude CLI

Mutation goes through `claude mcp add|remove`, never a direct edit of
~/.claude.json — the running CLI rewrites that file concurrently, so a
dashboard write would race it. Reads stay on readMcpServers.

The plan specified a --url flag; the real CLI (v2.1.266) has none —
commandOrUrl is positional, and --header must trail it or the variadic
flag swallows the url. Built against the verified shape.

server/routes/cc-config.js

@@ -10,9 +10,11 @@
  * artifacts (skills, agents, commands, output styles, memory, per-project
  * auto-memory), the structured keybindings.json editor, settings.json layers
  * via a per-key merge (`PATCH /settings`, which is also how hooks are edited),
- * and plugin/marketplace management delegated to the `claude plugin …` CLI.
- * Every file write is preceded by a timestamped backup. MCP server config
- * stays read-only — it is written concurrently by the running CLI.
+ * plugin/marketplace management delegated to the `claude plugin …` CLI, and
+ * MCP server add/remove delegated to the `claude mcp …` CLI. Every file
+ * write is preceded by a timestamped backup; the CLI-delegated writes are
+ * not files this server touches directly, so there is nothing to back up —
+ * the CLI owns `~/.claude.json`.
  *
  * Also hosts the auth-profile routes (`/profiles*`) that swap which Anthropic
  * account the local CLI runs as; those carry identity metadata only, never
@@ -25,6 +27,7 @@ const { Router } = require("express");
 const cc = require("../lib/cc-discovery");
 const ccMutate = require("../lib/cc-mutate");
 const ccCli = require("../lib/cc-plugin-cli");
+const ccMcpCli = require("../lib/cc-mcp-cli");
 const ccProfiles = require("../lib/cc-profiles");
 const { broadcast } = require("../websocket");
 
@@ -329,6 +332,43 @@ router.post("/marketplaces/action", async (req, res) => {
   }
 });
 
+// ── MCP servers (via the `claude` CLI) ─────────────────────────────────
+//
+// Same reasoning as the plugin/marketplace routes above: `~/.claude.json` is
+// rewritten concurrently by the running CLI, so add/remove shell out to
+// `claude mcp …` rather than editing the file. Reads are unaffected — GET
+// /mcp above stays on `readMcpServers`; the client refetches it after either
+// call below succeeds.
+
+router.post("/mcp/add", async (req, res) => {
+  const { name, scope, transport, command, args, url, headers, env } = req.body || {};
+  try {
+    const result = await ccMcpCli.mcpAdd({
+      name,
+      scope,
+      transport,
+      command,
+      args,
+      url,
+      headers,
+      env,
+    });
+    return cliResult(res, result, { action: "add", type: "mcp", name });
+  } catch (err) {
+    return cliError(res, err);
+  }
+});
+
+router.post("/mcp/remove", async (req, res) => {
+  const { name, scope } = req.body || {};
+  try {
+    const result = await ccMcpCli.mcpRemove({ name, scope });
+    return cliResult(res, result, { action: "remove", type: "mcp", name });
+  } catch (err) {
+    return cliError(res, err);
+  }
+});
+
 // PATCH /api/cc-config/settings — merge individual keys into one settings
 // layer. Body: { scope: "user"|"project"|"project-local", set?: {dotted: value},
 // unset?: ["dotted"] }. Hooks are edited through this same route as