fix(backup): nettoyer le fichier temporaire en cas d'erreur dans restore (#89)

Wraps temp file operations in try/except to ensure the temporary database file is always cleaned up, even if an exception occurs during write_snapshot or verify_integrity.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

test.ipynb

@@ -0,0 +1,71 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "initial_id",
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "import duckdb\n",
+    "\n",
+    "conn = duckdb.connect(\"tests/\")\n",
+    "cursor = conn.cursor()\n",
+    "df = cursor.execute(\"select * from decp limit 1\").pl()\n",
+    "df.columns"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "859cd599b5befafb",
+   "metadata": {
+    "ExecuteTime": {
+     "end_time": "2026-04-22T15:00:32.430249Z",
+     "start_time": "2026-04-22T15:00:31.843470Z"
+    }
+   },
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "True"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "import polars as pl\n",
+    "\n",
+    "schema = pl.read_parquet(\"../decp-processing/decp_prod.parquet\").schema\n",
+    "schema[\"dureeMois\"].is_integer()"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 2
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython2",
+   "version": "2.7.6"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}