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/transcription/build.rs

@@ -11,7 +11,7 @@
 //! workspace ever pulls `tokenizers` into the dependency graph on a
 //! Windows target. If we ever legitimately need it we can reintroduce
 //! it via a sidecar (isolated process, separate CRT) rather than
-//! linking it into `kon_lib`.
+//! linking it into `magnotia_lib`.
 //!
 //! The check is advisory on non-Windows targets — it still prints a
 //! cargo:warning if `tokenizers` appears, so the Windows failure isn't
@@ -56,7 +56,7 @@ fn main() {
 
     if target_os == "windows" {
         panic!(
-            "kon-transcription: the `tokenizers` crate appears in Cargo.lock and this is a \
+            "magnotia-transcription: the `tokenizers` crate appears in Cargo.lock and this is a \
              Windows build. Linking `whisper-rs-sys` + `tokenizers` in the same binary has \
              been a persistent MSVC C-runtime conflict (see Whispering v7.11.0). Route any \
              tokenizer usage through an out-of-process sidecar instead, or gate it off for \
@@ -65,7 +65,7 @@ fn main() {
     }
 
     println!(
-        "cargo:warning=kon-transcription: `tokenizers` crate is in the dependency graph. \
+        "cargo:warning=magnotia-transcription: `tokenizers` crate is in the dependency graph. \
          This build is non-Windows so the link will succeed, but Windows builds will panic \
          at build time per docs/whisper-ecosystem/brief.md item #6. Isolate tokenizer usage \
          in a sidecar before a Windows ship."