fix: replace AnyEvent WebSocket transport with Protocol::WebSocket (#290)

AnyEvent::WebSocket::Client's blocking ->recv() cannot run inside
pveproxy/pvedaemon (themselves built on AnyEvent as their core
reactor) without nesting event loops, which AnyEvent refuses by
design -- confirmed by a real user on the first real WebUI use of
v4.0.0, one day after release. Not a race condition: this fails on
every real "Add Storage" attempt against a WebSocket-transport host,
unconditionally. v4.0.0's testing never caught it because every
verification script ran standalone, never inside the actual daemon
process -- pvesm (a fresh CLI process) doesn't trigger it either, only
the real REST API path through pveproxy does.

Replaced _ws_connect/_ws_call's internals with Protocol::WebSocket::Client
+ IO::Socket::SSL -- a plain synchronous socket client with zero
event-loop dependency, so there's no shared reactor state to conflict
with pveproxy's. _api_ws's method-mapping logic is completely
unchanged; only the connection/call internals were rewritten.

Reproduced the exact bug via a real POST to /api2/json/storage through
pveproxy on a lab node, then confirmed the fix resolves it the same
way. Re-ran every check from v4.0.0's release (read path, write path,
snapshots, multipath) against the new transport -- zero regressions.

Full story: ADR-014, superseding ADR-012's library-choice section
only (everything else in ADR-012 stands). $VERSION bumped to 4.0.1.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/build.yml

@@ -36,7 +36,7 @@ jobs:
           sudo apt-get install -y \
             shellcheck libperl-critic-perl \
             libwww-perl libio-socket-ssl-perl libjson-perl \
-            libanyevent-perl libanyevent-websocket-client-perl
+            libprotocol-websocket-perl
 
           # Stub PVE modules not available outside Proxmox hosts
           mkdir -p /tmp/pve-stub/PVE/Storage