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/lib/utils/frontmatter.ts

@@ -43,7 +43,7 @@ function timeOfDayTag(dateStr: string): string | null {
   if (!dateStr) return null;
   let ts = Date.parse(dateStr);
   if (Number.isNaN(ts)) {
-    // Try DD/MM/YYYY, HH:MM:SS (UK local format used by Kon history rows).
+    // Try DD/MM/YYYY, HH:MM:SS (UK local format used by Magnotia history rows).
     const match = String(dateStr).match(
       /(\d{1,2})\/(\d{1,2})\/(\d{4})[,\s]+(\d{1,2}):(\d{2})(?::(\d{2}))?/,
     );
@@ -75,7 +75,7 @@ function sourceTag(source: string): string | null {
 // already shown elsewhere in the History row, so chips would duplicate
 // information and add cognitive load without improving retrieval. The
 // function is kept as a hook for one future AI-derived content tag
-// (`topic:*`) once kon-llm wires up real llama-cpp-2 in Phase 3.
+// (`topic:*`) once magnotia-llm wires up real llama-cpp-2 in Phase 3.
 export function deriveAutoTags(_item: TranscriptEntry): string[] {
   return [];
 }