feat(wake): long-poll wake listener for instant CLI sync

CLI now holds a GET /api/internal/agent/wake connection open.
When the server calls triggerWake(userId) — on stream request,
download queue, pause, cancel, resume, scan, etc. — the CLI
receives the signal immediately and fires a sync cycle in <100ms
instead of waiting up to 10s for the next scheduled interval.

- Add WaitForWake(ctx) to Client using a no-timeout HTTP client
- Add runWakeListener goroutine to SyncClient (auto-reconnects)
- Start wake listener from SyncClient.Run()

Closes: sub-second stream latency from the web UI

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.6.1] - 2026-04-08
+
+### Added
+
+- **wake**: long-poll `/api/internal/agent/wake` endpoint — CLI holds connection open and syncs immediately (<100ms) when server sends a wake signal instead of waiting for the next poll interval
+
 ## [0.6.0] - 2026-04-08