feat(kon): scaffold hybrid modular workspace

- Cargo workspace with 6 domain crates: core, audio, transcription, ai-formatting, storage, cloud-providers
- Minimal Tauri shell (lib.rs + main.rs) with plugin registration
- Svelte 5 frontend copied from Ramble v0.2
- All crates compile as empty stubs
- App identifier: uk.co.corbel.kon

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/lib/components/Toggle.svelte

@@ -0,0 +1,27 @@
+<script>
+  let { checked = $bindable(false), label = "", description = "" } = $props();
+</script>
+
+<div class="flex items-start gap-3 py-2.5">
+  <button
+    class="relative mt-0.5 w-[38px] min-w-[38px] h-[22px] rounded-full flex-shrink-0
+      {checked ? 'bg-accent shadow-[0_0_8px_rgba(232,168,124,0.25)]' : 'bg-border'}
+      active:scale-95 transition-all duration-200"
+    onclick={() => checked = !checked}
+    role="switch"
+    aria-checked={checked}
+    aria-label={label}
+  >
+    <span
+      class="absolute top-[3px] left-[3px] w-4 h-4 rounded-full bg-white shadow-sm
+        transition-transform duration-200 ease-[cubic-bezier(0.34,1.56,0.64,1)]
+        {checked ? 'translate-x-[16px]' : 'translate-x-0'}"
+    ></span>
+  </button>
+  <div class="flex-1 min-w-0">
+    <p class="text-[13px] text-text leading-tight">{label}</p>
+    {#if description}
+      <p class="text-[11px] text-text-tertiary mt-0.5 leading-snug">{description}</p>
+    {/if}
+  </div>
+</div>