fix(cli): honor json output for config get

Ensure `rig config get <key> --json` emits the documented value/source/default payload even when Commander records the option on the parent `config` command.

Verification:
- npm --workspace packages/cli test -- config.test.ts -t "rig config get <key> --json"
- npm --workspace packages/cli run build

Full `config.test.ts` still has the pre-existing driver-declared failure in `DaemonClient config integration > ConfigStore resolves non-default host/port from config file`.

packages/cli/src/commands/config.ts

@@ -84,7 +84,7 @@ Precedence: CLI flag > environment variable > config file > default`)
     .description("Read a single config value")
     .action((key: string, opts: { json?: boolean; showSource?: boolean }) => {
       try {
-        if (opts.json) {
+        if (opts.json || cmd.opts<{ json?: boolean }>().json) {
           console.log(JSON.stringify(store.resolveWithSource(key), null, 2));
           return;
         }

packages/cli/test/config.test.ts

@@ -266,6 +266,28 @@ describe("Config CLI", () => {
     expect(logs.join("\n")).toContain("transcripts");
   });
 
+  it("rig config get <key> --json prints value with source metadata", async () => {
+    const savedHost = process.env["OPENRIG_HOST"];
+    delete process.env["OPENRIG_HOST"];
+    const cmd = configCommand(join(tmpDir, "config.json"));
+    const prog = new Command();
+    prog.exitOverride();
+    prog.addCommand(cmd);
+
+    try {
+      const { logs } = await captureLogs(async () => {
+        await prog.parseAsync(["node", "rig", "config", "get", "daemon.host", "--json"]);
+      });
+      const parsed = JSON.parse(logs.join("\n"));
+      expect(parsed.value).toBe("127.0.0.1");
+      expect(parsed.source).toBe("default");
+      expect(parsed.defaultValue).toBe("127.0.0.1");
+    } finally {
+      if (savedHost === undefined) delete process.env["OPENRIG_HOST"];
+      else process.env["OPENRIG_HOST"] = savedHost;
+    }
+  });
+
   // Test 10
   it("rig config --help includes subcommands and examples", () => {
     const cmd = configCommand(join(tmpDir, "config.json"));