chore: rebrand from Kon/Corbie to Magnotia

Replace all instances of the legacy product names "Kon" and "Corbie" with
"Magnotia" across user-facing copy, code identifiers, package names, bundle
ids, file paths, and documentation. Preserves the unrelated "konsole" (KDE
terminal) reference and the parent CORBEL company name.

- Renames 10 Rust crates (kon-* → magnotia-*) and the tauri binary
- Updates package.json, tauri.conf.json (productName + identifier)
- Renames CSS classes (kon-rh-* → magnotia-rh-*) and animations
- Renames brand and roadmap docs
- Regenerates Cargo.lock and package-lock.json

Verified: svelte-check passes; pure-rust crates compile under new names.

crates/hotkey/src/lib.rs

@@ -1,4 +1,4 @@
-//! Wayland-compatible global hotkey listener for Kon.
+//! Wayland-compatible global hotkey listener for Magnotia.
 //!
 //! On Linux, reads `/dev/input/event*` devices via the `evdev` crate to capture
 //! global hotkeys without any display-server dependency. This works on both X11
@@ -8,7 +8,7 @@
 //! On non-Linux platforms, this crate is a no-op — the Tauri global-shortcut
 //! plugin handles hotkeys there.
 //!
-//! Architecture stolen from oddlama/whisper-overlay and adapted for Kon.
+//! Architecture stolen from oddlama/whisper-overlay and adapted for Magnotia.
 
 #[cfg(target_os = "linux")]
 mod linux;