feat: initialise workspace — Milestone 1 asset explorer

Three-crate Cargo workspace structured per PROJECT.md spec:
- crates/sylpheed-formats  — Xbox 360 format parsers (no Bevy)
- crates/sylpheed-viewer   — Bevy 0.15 asset viewer + egui UI
- crates/sylpheed-cli      — CLI tools (extract/list/sniff/texture)

Milestone 1 features:
- XISO disc image reading via xdvdfs 0.8
- XPR2 texture container parsing + Morton de-tiling
- D3DFORMAT → wgpu TextureFormat mapping (DXT1/3/5, DXN, ARGB)
- Custom Bevy AssetLoader for .xpr files
- Orbit camera (LMB orbit, RMB pan, scroll zoom)
- egui file browser + RE notes panel
- CLI: extract / list / sniff / texture info / texture export
- GitHub Actions CI (Linux, macOS, Windows, WASM)
- Trunk WASM build config

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

crates/sylpheed-formats/src/lib.rs

@@ -0,0 +1,30 @@
+//! # sylpheed-formats
+//!
+//! Asset format parsers for Project Sylpheed: Arc of Deception (Xbox 360).
+//!
+//! This crate handles:
+//! - Reading game files from XISO disc images (native only)
+//! - Parsing Xbox 360 texture formats (XPR2 containers + DXT de-tiling)
+//! - Parsing mesh formats (to be reverse engineered)
+//! - Parsing audio formats (XMA → standard PCM)
+//!
+//! ## Platform notes
+//! XISO reading is only available on native (Windows/macOS/Linux).
+//! On WASM, assets must be pre-extracted and served over HTTP.
+
+pub mod texture;
+pub mod vfs;
+
+// XISO reading is not available in-browser
+#[cfg(not(target_arch = "wasm32"))]
+pub mod xiso;
+
+// Mesh parsing — scaffold for reverse engineering
+pub mod mesh;
+
+// Audio parsing — scaffold for XMA handling
+pub mod audio;
+
+/// Re-export the most commonly used types at the crate root.
+pub use texture::{X360Texture, X360TextureFormat};
+pub use vfs::{GameAssets, VfsError};