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.

docs/brief/design-principles.md

@@ -1,4 +1,4 @@
-<!-- Source: Kon Master Brief — §4 Design Principles -->
+<!-- Source: Magnotia Master Brief — §4 Design Principles -->
 
 ### Design principles
 
@@ -21,7 +21,7 @@
 #### Interaction & UX
 - **Low-dopamine design.** Non-judgmental tone throughout. No guilt messaging for missed tasks. No aggressive review prompts.
 - **WIP limits as a design constraint.** The interface must never present more than 1–3 active tasks simultaneously on the primary view. AI prioritises; the UI constrains. A brain dump can contain 50 items — the "Now" view shows only the next action. This is not a nice-to-have; it is the core mechanism for preventing the freeze response.
-- **Automated context restoration.** Working memory traces decay within ~8 seconds of interruption. If a user clicks away, gets distracted, or closes the app mid-task, Kon must perfectly preserve their exact state — cursor position, active timer, active task, scroll position — so they can resume with zero "Where was I?" cognitive latency. This must be seamless and automatic. No "Resume session?" dialogue. Just open the app and be exactly where you left off.
+- **Automated context restoration.** Working memory traces decay within ~8 seconds of interruption. If a user clicks away, gets distracted, or closes the app mid-task, Magnotia must perfectly preserve their exact state — cursor position, active timer, active task, scroll position — so they can resume with zero "Where was I?" cognitive latency. This must be seamless and automatic. No "Resume session?" dialogue. Just open the app and be exactly where you left off.
 - **Literal labels always.** Ambiguous icons (standalone gear, hamburger menu) force literal thinkers to guess function, expending precious mental energy. Always pair icons with literal text labels.
 - **Progressive disclosure.** Break complex onboarding or tasks down to reveal only the immediate next step, preventing the brain from freezing.
 - **Motion control.** All non-essential animation and auto-playing media must be off by default or controlled via a prominent "Reduce Motion" / "Calm Mode" toggle. Unexpected animations can cause physical distress and sensory overload.
@@ -29,7 +29,7 @@
 
 #### Onboarding
 - Must be understandable within 30 seconds. If a neurodivergent user can't figure it out immediately, they won't return.
-- **90-second hard threshold.** Empirical HCI research (see Appendix A4) shows that tools taking longer than 90 seconds to configure trigger task abandonment cascades in ADHD users, increasing cognitive load by 2.3x. No feature in Kon should require more than 90 seconds of setup. Voice capture must work in under 3 seconds from app open.
+- **90-second hard threshold.** Empirical HCI research (see Appendix A4) shows that tools taking longer than 90 seconds to configure trigger task abandonment cascades in ADHD users, increasing cognitive load by 2.3x. No feature in Magnotia should require more than 90 seconds of setup. Voice capture must work in under 3 seconds from app open.
 - Progressive disclosure applies here especially — show one step at a time, never the full complexity.
 
 #### Future consideration: adaptive UI