xenia-kernel: HLE expansion, scheduler integration, audit + UI bridge

Major HLE buildout in exports.rs: KeInitializeSemaphore now seeds
count/limit, XexGet{Module,Procedure}Address use distinct
HMODULE_XBOXKRNL/HMODULE_XAM pseudo-handles with a reverse
(ModuleId,ordinal)→thunk_addr map, plus sweeping additions across
sync primitives, file I/O, semaphores, events, threads, and
allocator paths needed to advance Sylpheed past VdSwap=2.

New modules:
  - thread.rs   — ThreadRef + per-thread suspension/wake plumbing
  - interrupts.rs — IRQ delivery, pending-IRQ slots, IPI helpers
  - path.rs     — guest path normalization (D:\\, game:\\, etc.)
  - audit.rs    — --trace-handles harness backing the handle audit
  - ui_bridge.rs — kernel-side endpoint of the xenia-ui bridge
                   (input snapshots, framebuffer publish handles)

state.rs grows to own the HW-slot scheduler state, the new audit /
UI bridge handles, and the per-handle reverse maps. xam.rs and
objects.rs follow suit for the HLE additions.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/xenia-kernel/Cargo.toml

@@ -8,6 +8,10 @@ license.workspace = true
 xenia-types = { workspace = true }
 xenia-memory = { workspace = true }
 xenia-cpu = { workspace = true }
+xenia-vfs = { workspace = true }
+xenia-hid = { workspace = true }
+xenia-gpu = { workspace = true }
 tracing = { workspace = true }
+metrics = { workspace = true }
 thiserror = { workspace = true }
 anyhow = { workspace = true }