Initial commit: xenia-rs workspace for Xbox 360 RE

Rust reimplementation of the xenia Xbox 360 emulator targeting reverse-
engineering and preservation, initially scoped to Project Sylpheed.

Includes:
- XEX2 loader (LZX decompression, AES decryption, PE parsing)
- XISO / XGD2 disc image VFS
- PPC interpreter with 200+ opcodes and VMX128 decoding
- Static analyzer: functions, cross-references, labels, asm + SQLite output
- HLE kernel covering the xboxkrnl/xam subset used by Sylpheed init
- Debugger with in-memory and SQLite-backed execution tracing
- `xenia-rs` CLI with extract/dis/exec commands that produce cumulative,
  superset SQLite databases and opt-in instruction/import/branch traces

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/xenia-vfs/src/device.rs

@@ -0,0 +1,54 @@
+use crate::{VfsDevice, VfsEntry, VfsError};
+use std::path::{Path, PathBuf};
+
+/// Host filesystem pass-through device.
+pub struct HostPathDevice {
+    name: String,
+    root: PathBuf,
+}
+
+impl HostPathDevice {
+    pub fn new(name: impl Into<String>, root: impl AsRef<Path>) -> Self {
+        Self {
+            name: name.into(),
+            root: root.as_ref().to_path_buf(),
+        }
+    }
+}
+
+impl VfsDevice for HostPathDevice {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn list_root(&self) -> Result<Vec<VfsEntry>, VfsError> {
+        let mut entries = Vec::new();
+        for entry in std::fs::read_dir(&self.root)? {
+            let entry = entry?;
+            let metadata = entry.metadata()?;
+            entries.push(VfsEntry {
+                name: entry.file_name().to_string_lossy().into_owned(),
+                is_directory: metadata.is_dir(),
+                size: metadata.len(),
+                offset: 0,
+            });
+        }
+        Ok(entries)
+    }
+
+    fn read_file(&self, path: &str) -> Result<Vec<u8>, VfsError> {
+        let full_path = self.root.join(path);
+        std::fs::read(&full_path).map_err(VfsError::from)
+    }
+
+    fn stat(&self, path: &str) -> Result<VfsEntry, VfsError> {
+        let full_path = self.root.join(path);
+        let metadata = std::fs::metadata(&full_path)?;
+        Ok(VfsEntry {
+            name: path.to_string(),
+            is_directory: metadata.is_dir(),
+            size: metadata.len(),
+            offset: 0,
+        })
+    }
+}