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/linux.rs

@@ -89,7 +89,7 @@ impl EvdevHotkeyListener {
                             Ok(()) => Some(w),
                             Err(e) => {
                                 eprintln!(
-                                    "[kon-hotkey] cannot watch /dev/input ({e}); \
+                                    "[magnotia-hotkey] cannot watch /dev/input ({e}); \
                                  hotplug detection disabled, devices present \
                                  at startup still work",
                                 );
@@ -99,7 +99,7 @@ impl EvdevHotkeyListener {
                     }
                     Err(e) => {
                         eprintln!(
-                            "[kon-hotkey] cannot create inotify watcher ({e}); \
+                            "[magnotia-hotkey] cannot create inotify watcher ({e}); \
                              hotplug detection disabled",
                         );
                         None