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/routes/+page.svelte

@@ -0,0 +1,29 @@
+<script>
+  import { page } from "$lib/stores/page.svelte.js";
+  import DictationPage from "$lib/pages/DictationPage.svelte";
+  import FilesPage from "$lib/pages/FilesPage.svelte";
+  import TasksPage from "$lib/pages/TasksPage.svelte";
+  import HistoryPage from "$lib/pages/HistoryPage.svelte";
+  import SettingsPage from "$lib/pages/SettingsPage.svelte";
+
+  // Redirect legacy "profiles" page to settings
+  $effect(() => {
+    if (page.current === "profiles") page.current = "settings";
+  });
+</script>
+
+<div class="h-full overflow-hidden">
+  {#key page.current}
+    {#if page.current === "dictation"}
+      <DictationPage />
+    {:else if page.current === "files"}
+      <FilesPage />
+    {:else if page.current === "tasks"}
+      <TasksPage />
+    {:else if page.current === "history"}
+      <HistoryPage />
+    {:else if page.current === "settings"}
+      <SettingsPage />
+    {/if}
+  {/key}
+</div>