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/hardware.rs

@@ -1,7 +1,7 @@
 use serde::Serialize;
 
-use kon_core::hardware::{self, Os};
-use kon_core::recommendation;
+use magnotia_core::hardware::{self, Os};
+use magnotia_core::recommendation;
 
 #[derive(Serialize)]
 pub struct SystemInfo {
@@ -53,7 +53,7 @@ pub fn rank_models() -> Result<Vec<ModelRecommendation>, String> {
     Ok(ranked
         .into_iter()
         .map(|scored| {
-            let downloaded = kon_transcription::is_downloaded(&scored.entry.id);
+            let downloaded = magnotia_transcription::is_downloaded(&scored.entry.id);
             ModelRecommendation {
                 id: scored.entry.id.as_str().to_string(),
                 display_name: scored.entry.display_name,