perf(lyrics): fix CPU spikes during lyric transitions; fix release workflow

CSS: remove `font-weight` from transition list on `.fs-lyric-line` — it
triggers layout reflow on every animation frame when the active line changes.
Replaced with `transform: scaleX(1.015)` on `.fsl-active` (compositor-only).
Added `contain: layout style` to `.fs-lyrics-overlay` to isolate reflows.

Cargo.lock: update for thread-priority crate (added in previous audio commit).

CI: replace delete-asset workaround with `updaterJsonKeepUniversal: false`
to prevent tauri-action from uploading a latest.json with wrong signature.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src-tauri/Cargo.lock

@@ -3442,6 +3442,7 @@ dependencies = [
  "tauri-plugin-store",
  "tauri-plugin-updater",
  "tauri-plugin-window-state",
+ "thread-priority",
  "tokio",
  "url",
 ]
@@ -3513,7 +3514,7 @@ dependencies = [
  "once_cell",
  "socket2 0.6.3",
  "tracing",
- "windows-sys 0.52.0",
+ "windows-sys 0.60.2",
 ]
 
 [[package]]
@@ -5295,6 +5296,20 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "thread-priority"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cfe075d7053dae61ac5413a34ea7d4913b6e6207844fd726bdd858b37ff72bf5"
+dependencies = [
+ "bitflags 2.11.0",
+ "cfg-if",
+ "libc",
+ "log",
+ "rustversion",
+ "winapi",
+]
+
 [[package]]
 name = "time"
 version = "0.3.45"