chore(cleanup): drop TEMP cursor probes + clear KWin-leg clippy debt

The KWin/Phase-A/B commits were built but never clippy-checked (that distrobox
had no clippy component), so they left TEMP on-glass probes and lint debt in the
tree. With clippy now runnable (fedora rust 1.96.1 = CI parity):

- drop the `fec424ee`/`8cff30d5` TEMP probes: the `update_cursor_meta` SPA_META
  diagnostic logs (also un-detaches the `// SAFETY:` comment from its `unsafe`
  block → fixes `undocumented_unsafe_blocks`) and the KWin composite-arm probe in
  the encode loop.
- `#[allow(clippy::too_many_arguments)]` on `spawn_pipewire` (8 params since the
  KWin leg added `expect_exact_dims`; mirrors `from_virtual_output`).

clippy `-p pf-capture -p pf-vdisplay -p punktfunk-host --locked --features
nvenc,vulkan-encode -- -D warnings` is now green. (--all-targets additionally
trips a pre-existing env mismatch: the fedora libspa binding lacks
`SPA_VIDEO_TRANSFER_SMPTE2084`, referenced only by a `#[cfg(test)]` guard-test —
not a code issue; CI's pinned pipewire has it.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/pf-inject/src/inject/linux/libei.rs

@@ -763,7 +763,9 @@ impl EiState {
                         // raw client pixels as the last resort.
                         let nx = (ev.x as f32 / w).clamp(0.0, 1.0);
                         let ny = (ev.y as f32 / h).clamp(0.0, 1.0);
-                        let (x, y) = match region_for_mode(slot.regions(), w, h).filter(|r| sane_region(r)) {
+                        let (x, y) = match region_for_mode(slot.regions(), w, h)
+                            .filter(|r| sane_region(r))
+                        {
                             Some(region) => (
                                 region.x as f32 + nx * region.width as f32,
                                 region.y as f32 + ny * region.height as f32,
@@ -846,7 +848,9 @@ impl EiState {
                         let nx = (ev.x as f32 / w).clamp(0.0, 1.0);
                         let ny = (ev.y as f32 / h).clamp(0.0, 1.0);
                         // Same region-selection + degenerate fallback ladder as MouseMoveAbs.
-                        let (x, y) = match region_for_mode(slot.regions(), w, h).filter(|r| sane_region(r)) {
+                        let (x, y) = match region_for_mode(slot.regions(), w, h)
+                            .filter(|r| sane_region(r))
+                        {
                             Some(region) => (
                                 region.x as f32 + nx * region.width as f32,
                                 region.y as f32 + ny * region.height as f32,