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/ai-formatting/src/to_plain_text.rs

@@ -7,13 +7,13 @@
 //! structure) degraded cleanup quality materially; plain-text input
 //! raised it back.
 //!
-//! `Segment.text` in Kon already holds just the spoken text (the
+//! `Segment.text` in Magnotia already holds just the spoken text (the
 //! `start`/`end` f64 fields carry the timing), so "timestamp
 //! stripping" falls out of using the text field alone. The work here
 //! is the whitespace pass and empty-segment filter, plus a single
 //! public function the pipeline can depend on.
 
-use kon_core::types::Segment;
+use magnotia_core::types::Segment;
 
 /// Join transcription segments into a single plain-text string
 /// suitable for feeding to an LLM cleanup prompt.