feat(session): Skia console UI — overlay contract + stats OSD/capture HUD (phase 4a)

The §6.1 presenter↔console-UI contract lands: pf-presenter exposes its
device (SharedDevice) and composites at most one premultiplied-alpha
quad per frame (new overlay.frag + LOAD render pass over the swapchain;
zero cost while the overlay returns None). pf-console-ui implements it
with skia-safe on the shared VkDevice: DirectContext via the ash
dispatch chain, a ring of two offscreen render targets (one-frame-in-
flight safe), damage-driven redraws — the OSD re-renders at 1 Hz, the
hint on capture toggles, nothing per-frame. Skia never touches the
swapchain. The session binary carries it behind the default ui feature:
4.9 MB stripped without, 10 MB with (measured).

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

crates/pf-console-ui/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "pf-console-ui"
+description = "The Skia console UI for the Vulkan session binary — stats OSD, capture HUD, and (next) the gamepad library; renders on the presenter's device via the Overlay contract"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+authors.workspace = true
+repository.workspace = true
+
+[target.'cfg(target_os = "linux")'.dependencies]
+pf-presenter = { path = "../pf-presenter" }
+
+# Skia on the presenter's VkDevice (`vulkan`); `textlayout` = skparagraph/harfbuzz for
+# the typography the console library needs (~15 MB stripped, prebuilt binaries exist for
+# this feature set on x86_64-unknown-linux-gnu — a source build is never triggered).
+skia-safe = { version = "0.87", features = ["vulkan", "textlayout"] }
+ash = { version = "0.38", features = ["loaded"] }
+sdl3 = { version = "0.18", features = ["hidapi", "ash"] }
+
+anyhow = "1"
+tracing = "0.1"