feat(history): migrate history to SQLite with FTS5 search

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

src/lib/pages/FilesPage.svelte

@@ -2,7 +2,8 @@
   import { onMount, onDestroy } from "svelte";
   import { invoke } from "@tauri-apps/api/core";
   import { listen } from "@tauri-apps/api/event";
-  import { settings, addToHistory } from "$lib/stores/page.svelte.js";
+  import { settings } from "$lib/stores/page.svelte.js";
+  import { loadHistory } from "$lib/stores/history.svelte.js";
   import Card from "$lib/components/Card.svelte";
   import EmptyState from "$lib/components/EmptyState.svelte";
   import { exportTranscript } from "$lib/utils/export.js";
@@ -91,16 +92,9 @@
 
         segments = [...segments, ...result.segments];
 
-        addToHistory({
-          id: crypto.randomUUID(),
-          date: new Date().toLocaleString("en-GB"),
-          source: fileName,
-          preview: text.slice(0, 120),
-          text,
-          segments: result.segments,
-          duration: result.duration,
-          language: result.language,
-        });
+        // transcribe_file auto-persists to SQLite (Task 2).
+        // Refresh local history state to pick up the new entry.
+        loadHistory();
       } catch (err) {
         error = `Failed: ${fileName} — ${typeof err === "string" ? err : err.message}`;
       }