lembas remote: manage remote: without YAML; a running service follows it

`lembas remote list | add | remove | enable | disable | mode | terminal`, with
`--json` printing {enabled, roots, max_mode, terminal}, for LLeMbas Desktop.
Writes go through the global config writer and keep comments.

The device's limits are now live getters over the remote: block, re-read when
config.yaml's stat changes. `lembas service` links even with remote work off
or no roots: it says roots: [] and refuses every session, directory and
terminal, so the instance can tell "no folder allowed yet" from "not running".
When what the instance was told changes, the link re-dials once nothing is
working, so `lembas remote add` or `enable` takes effect without a restart.
Harness spec 1.0.1 documents both.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/acp.test.ts

@@ -6,7 +6,7 @@ import { mkdirSync, mkdtempSync, realpathSync, writeFileSync } from "node:fs"
 import { tmpdir } from "node:os"
 import { join } from "node:path"
 import { AcpAgent, clampMode, underRoots, type Limits } from "../src/acp/agent.ts"
-import { LinkError, runLink } from "../src/acp/link.ts"
+import { runLink } from "../src/acp/link.ts"
 import { Peer, type Transport } from "../src/acp/rpc.ts"
 import { paths } from "../src/config/paths.ts"
 import { setTrust } from "../src/project/root.ts"
@@ -300,14 +300,6 @@ test("an approval nobody answers is a denial", async () => {
   expect(fake.requests[1].messages.at(-1).content).toContain("Nobody answered")
 })
 
-test("the link: off unless the device says so", async () => {
-  mkdirSync(paths.config, { recursive: true })
-  writeFileSync(join(paths.config, "config.yaml"), "")
-  await expect(runLink()).rejects.toBeInstanceOf(LinkError)
-  writeFileSync(join(paths.config, "config.yaml"), "remote:\n  enabled: true\n")
-  await expect(runLink()).rejects.toThrow("remote.roots is empty")
-})
-
 test("the link dials out with the token, says hello, is driven, and stops when refused", async () => {
   fake = fakeProvider([{ chunks: [delta({ content: "linked reply" })] }])
   const root = project()