Release 0.6.3 — in-app screen-sharing controls + hwdec fixes

Bump to 0.6.3 and document the screen-share work merged on this branch:
the advanced Settings section + per-call quality picker (96e41de), the
hardware-decode-defaults-off frame-1 freeze fix (96e41de), the per-call
quality override fix (e378b2e), and the VLC-honors-viewer-settings fix
(faad8ce). All local-only — no wire-protocol change, old configs load
unchanged.

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

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "peerspeak"
-version = "0.6.2"
+version = "0.6.3"
 edition = "2024"
 description = "Decentralized peer-to-peer voice chat (Rust/iroh/PipeWire/Opus/iced)"
 license = "MIT"