v0.0.40: reliability — call reload, ETH cache prefill, 10 server tests

Call state reload on restart:
- Loads Ringing/Active calls from sled into active_calls on startup
- Expires calls older than 24h automatically

TUI sender ETH cache prefill:
- prefill_eth_cache() resolves all known contacts on poll_loop start
- First message from known contacts now shows ETH address immediately

Server integration tests (10 new):
- push_to_client offline/online
- register_ws + connection cap (5 max)
- is_online + device_count
- kick_device + revoke_all_except
- deliver_or_queue offline/online
- call state lifecycle
- list_devices

155 tests passing (was 135)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/crates/warzone-server/src/routes/web.rs

@@ -50,7 +50,7 @@ async fn pwa_manifest() -> impl IntoResponse {
 
 async fn service_worker() -> impl IntoResponse {
     ([(header::CONTENT_TYPE, "application/javascript")], r##"
-const CACHE = 'wz-v21';
+const CACHE = 'wz-v22';
 const SHELL = ['/', '/wasm/warzone_wasm.js', '/wasm/warzone_wasm_bg.wasm', '/icon.svg', '/manifest.json'];
 
 self.addEventListener('install', e => {
@@ -287,7 +287,7 @@ let pollTimer = null;
 let ws = null;  // WebSocket connection
 let wasmReady = false;
 
-const VERSION = '0.0.39';
+const VERSION = '0.0.40';
 let DEBUG = true;  // toggle with /debug command
 
 // ── Receipt tracking ──