feat(ui): add export section to SettingsPage with directory picker and format selection

Export Your Data section with three buttons: Export Transcriptions (MD/TXT),
Export Tasks (JSON/CSV), and Export to Obsidian. Each opens a directory picker
and shows status on completion.

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

src/lib/pages/SettingsPage.svelte

@@ -10,7 +10,7 @@
   import ZonePicker from "$lib/components/ZonePicker.svelte";
   import AccessibilityControls from "$lib/components/AccessibilityControls.svelte";
   import { getPreferences, updatePreferences } from "$lib/stores/preferences.svelte.js";
-  import { Check, ChevronRight } from "lucide-svelte";
+  import { Check, ChevronRight, Download } from "lucide-svelte";
   import { open } from "@tauri-apps/plugin-dialog";
 
   const prefs = getPreferences();
@@ -173,6 +173,37 @@
     }
   }
 
+  // --- Export state ---
+  let exportTranscriptFormat = $state("md");
+  let exportTaskFormat = $state("json");
+  let exportStatus = $state("");
+  let exporting = $state("");
+
+  async function doExport(type) {
+    try {
+      const folder = await open({ directory: true, title: "Select export folder" });
+      if (!folder) return;
+
+      exporting = type;
+      exportStatus = "";
+
+      if (type === "transcriptions") {
+        const count = await invoke("export_transcriptions", { directory: folder, format: exportTranscriptFormat });
+        exportStatus = count === 0 ? "No transcriptions yet" : `Exported ${count} transcription${count === 1 ? "" : "s"} to ${folder}`;
+      } else if (type === "tasks") {
+        const path = await invoke("export_tasks", { directory: folder, format: exportTaskFormat });
+        exportStatus = `Tasks exported to ${path}`;
+      } else if (type === "obsidian") {
+        const count = await invoke("export_to_obsidian", { directory: folder });
+        exportStatus = count === 0 ? "Nothing to export yet" : `Exported ${count} file${count === 1 ? "" : "s"} to ${folder}`;
+      }
+    } catch (err) {
+      exportStatus = typeof err === "string" ? err : "Export failed";
+    } finally {
+      exporting = "";
+    }
+  }
+
   // --- Profile management ---
   function createProfile() {
     if (!newProfileName.trim()) return;
@@ -621,6 +652,86 @@
         {/if}
       </div>
 
+      <!-- Export -->
+      <div class="border-b border-border-subtle">
+        <button
+          class="flex items-center justify-between w-full py-4 px-5 text-left"
+          onclick={() => openSection = openSection === 'export' ? null : 'export'}
+        >
+          <h3 class="font-display text-[18px] italic text-text">Export Your Data</h3>
+          <span class="text-text-tertiary text-[16px] leading-none">{openSection === 'export' ? '−' : '+'}</span>
+        </button>
+        {#if openSection === 'export'}
+          <div class="px-5 pb-5 animate-fade-in">
+            <p class="text-[11px] text-text-tertiary mb-4">All your data stays yours. Export everything as plain text files.</p>
+
+            <div class="space-y-3">
+              <!-- Export Transcriptions -->
+              <div class="flex items-center gap-3">
+                <button
+                  class="flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-[12px] font-medium
+                         bg-accent/10 text-accent hover:bg-accent/20 disabled:opacity-50"
+                  disabled={exporting === "transcriptions"}
+                  onclick={() => doExport("transcriptions")}
+                >
+                  <Download class="w-3.5 h-3.5" />
+                  {exporting === "transcriptions" ? "Exporting..." : "Export Transcriptions"}
+                </button>
+                <select
+                  class="bg-bg-input border border-border-subtle rounded-lg px-2 py-1 text-[11px] text-text-secondary
+                         focus:outline-none focus:border-accent appearance-none cursor-pointer"
+                  bind:value={exportTranscriptFormat}
+                >
+                  <option value="md">Markdown</option>
+                  <option value="txt">Plain Text</option>
+                </select>
+              </div>
+
+              <!-- Export Tasks -->
+              <div class="flex items-center gap-3">
+                <button
+                  class="flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-[12px] font-medium
+                         bg-accent/10 text-accent hover:bg-accent/20 disabled:opacity-50"
+                  disabled={exporting === "tasks"}
+                  onclick={() => doExport("tasks")}
+                >
+                  <Download class="w-3.5 h-3.5" />
+                  {exporting === "tasks" ? "Exporting..." : "Export Tasks"}
+                </button>
+                <select
+                  class="bg-bg-input border border-border-subtle rounded-lg px-2 py-1 text-[11px] text-text-secondary
+                         focus:outline-none focus:border-accent appearance-none cursor-pointer"
+                  bind:value={exportTaskFormat}
+                >
+                  <option value="json">JSON</option>
+                  <option value="csv">CSV</option>
+                </select>
+              </div>
+
+              <!-- Export to Obsidian -->
+              <div class="flex items-center gap-3">
+                <button
+                  class="flex items-center gap-1.5 px-3 py-1.5 rounded-lg text-[12px] font-medium
+                         bg-accent/10 text-accent hover:bg-accent/20 disabled:opacity-50"
+                  disabled={exporting === "obsidian"}
+                  onclick={() => doExport("obsidian")}
+                >
+                  <Download class="w-3.5 h-3.5" />
+                  {exporting === "obsidian" ? "Exporting..." : "Export to Obsidian"}
+                </button>
+                <span class="text-[10px] text-text-tertiary">Markdown + wikilinks, both transcriptions and tasks</span>
+              </div>
+            </div>
+
+            {#if exportStatus}
+              <p class="text-[11px] text-text-secondary mt-3 bg-bg-input rounded-lg px-3 py-2 border border-border-subtle">
+                {exportStatus}
+              </p>
+            {/if}
+          </div>
+        {/if}
+      </div>
+
       <!-- Hotkey -->
       <div class="border-b border-border-subtle">
         <button