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.

src-tauri/src/commands/paste.rs

@@ -11,7 +11,7 @@
 //! ydotool / osascript / SendKeys), so we probe and fall back.
 //!
 //! NOTE: focus must already be on the target window when the keystroke
-//! fires. The global hotkey flow preserves this naturally; clicking Kon's
+//! fires. The global hotkey flow preserves this naturally; clicking Magnotia's
 //! window does not. The frontend surfaces this caveat next to the toggle.
 
 use std::process::Command;
@@ -57,10 +57,10 @@ pub struct PasteOutcome {
 /// focused window. Returns a structured result so the frontend can surface
 /// partial success (clipboard set, paste failed).
 ///
-/// Wayland compositor quirk: if Kon's always-on-top preview overlay is
+/// Wayland compositor quirk: if Magnotia's always-on-top preview overlay is
 /// visible when the keystroke fires, KWin / Mutter may resolve the keystroke
 /// against the overlay (even with `focused: false` set at build time) and
-/// the paste lands inside Kon instead of the previously-focused app. We hide
+/// the paste lands inside Magnotia instead of the previously-focused app. We hide
 /// the preview window and give the compositor a beat to re-focus the real
 /// target before dispatching. Matches OpenWhispr's PR #246 fix on GNOME.
 #[tauri::command]