chore(release): bump workspace version to 0.8.4

Release 0.8.4 — reconnect reliability and streaming polish over 0.8.3.

The headline fix: a reconnect to a saved host that had stopped advertising on
mDNS (but still had a learned Wake-on-LAN MAC) was routed into a wait-for-mDNS
wake flow instead of being dialed — so a host reached over a routed network
(Tailscale/VPN/another subnet) could never be reconnected, reading as "Offline"
with no connection attempt in the host log. All four full clients now dial
first and only fall into the visible "Waking…" wait when the dial actually
fails. On the host side, the same investigation surfaced Windows-only gaps: a
deliberate quit (⌘D) now tears the pf-vdisplay virtual monitor down immediately
(no 10 s linger churning the reconnect's REMOVE→ADD), while keep_alive=forever
(the gaming-rig preset) correctly outranks the quit on both platforms so a
pinned screen stays alive. Silent deaths are no longer invisible: a panic hook
tees panics into the web console's Logs, a Windows SEH filter names the faulting
module on a native GPU-driver crash, and a watchdog flags a wedged monitor
teardown.

Also in this release: the presenter switches to MAILBOX present, pushes HDR10
mastering metadata, and tags HDR honestly; DualSense rumble accepts the v2
vibration valid-flag and bounds a stale buzz; the core caps the QUIC datagram
send buffer so audio/rumble go latest-wins; the host folds a Steam Deck to a
DualSense on Windows (split-pad touch + pad clicks) and applies input motion on
arrival rather than after the 4 ms tick; Android gains a tiered stats HUD with
windowed lost/skipped/FEC counters; and Windows surfaces a Help/shortcuts
screen and exits fullscreen when the stream stops.

The [workspace.package] version (inherited by every crate via version.workspace)
is the release being cut; the 14 workspace entries in Cargo.lock and the
api/openapi.json info.version are refreshed to match (CI builds --locked).
Canary derives from the tag as minor+1 of the latest stable
(scripts/ci/pf-version.sh), so cutting 0.8.4 keeps canary at 0.9.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Cargo.toml

@@ -22,7 +22,7 @@ members = [
 exclude = ["packaging/linux/steam-deck-gadget/usbip-poc"]
 
 [workspace.package]
-version = "0.8.3"
+version = "0.8.4"
 edition = "2021"
 rust-version = "1.82"
 license = "MIT OR Apache-2.0"