fix: MediaRecorder crash on rapid re-record + add sample sort_order and reorder API

app/src/i18n/locales/en/translation.json

@@ -369,7 +369,7 @@
     "editTranscription": "Edit transcription",
     "deleteSample": "Delete sample",
     "addSample": "Add Sample",
-    "note": "Note: A single 30-second sample is the sweet spot. Quality may decrease with multiple samples. In a future update samples might be interchangeable and tagged for varying styles of the same voice.",
+    "note": "Add multiple samples to improve voice quality — more diverse recordings produce better results. Samples are automatically combined.",
     "deleteDialog": {
       "title": "Delete Sample",
       "description": "Are you sure you want to delete this audio sample? This action cannot be undone.",

app/src/i18n/locales/ja/translation.json

@@ -369,7 +369,7 @@
     "editTranscription": "文字起こしを編集",
     "deleteSample": "サンプルを削除",
     "addSample": "サンプルを追加",
-    "note": "メモ:30 秒のサンプル 1 本が最適です。サンプルを複数追加すると品質が低下することがあります。今後のアップデートで、同じボイスの異なるスタイル向けにサンプルを切り替え可能にし、タグ付けできるようにするかもしれません。",
+    "note": "複数のサンプルを追加すると音声品質が向上します — 多様な録音ほど良い結果が得られます。サンプルは自動的に結合されます。",
     "deleteDialog": {
       "title": "サンプルを削除",
       "description": "このオーディオサンプルを本当に削除しますか? この操作は元に戻せません。",

app/src/i18n/locales/zh-CN/translation.json

@@ -369,7 +369,7 @@
     "editTranscription": "编辑转录",
     "deleteSample": "删除样本",
     "addSample": "添加样本",
-    "note": "注意:单个 30 秒的样本效果最佳。多个样本可能会降低质量。未来版本中样本可能会变得可互换,并为同一声音的不同风格打标签。",
+    "note": "添加多个样本可提升音质 — 录音越多样化，效果越好。样本将自动合并。",
     "deleteDialog": {
       "title": "删除样本",
       "description": "确定要删除此音频样本吗?此操作不可撤销。",

app/src/i18n/locales/zh-TW/translation.json

@@ -369,7 +369,7 @@
     "editTranscription": "編輯轉錄",
     "deleteSample": "刪除樣本",
     "addSample": "新增樣本",
-    "note": "注意:單一 30 秒的樣本效果最佳。多個樣本可能會降低品質。未來版本中樣本可能可互換,並為同一聲音的不同風格加上標籤。",
+    "note": "添加多個樣本可提升音質 — 錄音越多樣化，效果越好。樣本將自動合併。",
     "deleteDialog": {
       "title": "刪除樣本",
       "description": "確定要刪除此音訊樣本嗎?此操作無法復原。",

app/src/lib/api/models/ProfileSampleResponse.ts

@@ -10,4 +10,5 @@ export type ProfileSampleResponse = {
   profile_id: string;
   audio_path: string;
   reference_text: string;
+  sort_order: number;
 };

app/src/lib/api/schemas/$ProfileSampleResponse.ts

@@ -21,5 +21,9 @@ export const $ProfileSampleResponse = {
       type: 'string',
       isRequired: true,
     },
+    sort_order: {
+      type: 'number',
+      isRequired: true,
+    },
   },
 } as const;

app/src/lib/hooks/useAudioRecording.ts

@@ -21,12 +21,18 @@ export function useAudioRecording({
   const timerRef = useRef<number | null>(null);
   const startTimeRef = useRef<number | null>(null);
   const cancelledRef = useRef<boolean>(false);
+  // Monotonically-increasing session counter.  Each call to startRecording
+  // increments it; the onstop closure captures it and bails out if it no
+  // longer matches — prevents a slow convertToWav from a previous session
+  // from calling onRecordingComplete after a new recording has already begun.
+  const sessionRef = useRef<number>(0);
 
   const startRecording = useCallback(async () => {
     try {
       setError(null);
       chunksRef.current = [];
       cancelledRef.current = false;
+      sessionRef.current += 1;
       setDuration(0);
 
       // Check if getUserMedia is available
@@ -88,6 +94,12 @@ export function useAudioRecording({
         }
       };
 
+      // Capture the session ID for this recording at the time the recorder
+      // is set up.  If the user starts a new recording before the async
+      // onstop work finishes (e.g. convertToWav is slow), the new session
+      // will have a different ID and we skip the stale completion callback.
+      const thisSession = sessionRef.current;
+
       mediaRecorder.onstop = async () => {
         // Snapshot the cancellation flag and recorded duration immediately —
         // cancelRecording() clears chunks and sets cancelledRef synchronously
@@ -105,17 +117,32 @@ export function useAudioRecording({
         });
         streamRef.current = null;
 
+        // Clear the recorder ref now that it's done — prevents stopRecording
+        // from accidentally operating on an already-stopped MediaRecorder if
+        // the user clicks stop again before state catches up.
+        if (mediaRecorderRef.current === mediaRecorder) {
+          mediaRecorderRef.current = null;
+        }
+
         // Don't fire completion callback if the recording was cancelled
         if (wasCancelled) return;
 
+        // Don't fire completion callback if a newer session has started
+        if (sessionRef.current !== thisSession) return;
+
         // Convert to WAV format to avoid needing ffmpeg on backend
         try {
           const wavBlob = await convertToWav(webmBlob);
-          onRecordingComplete?.(wavBlob, recordedDuration);
+          // Final guard: still belongs to this session?
+          if (sessionRef.current === thisSession) {
+            onRecordingComplete?.(wavBlob, recordedDuration);
+          }
         } catch (err) {
           console.error('Error converting audio to WAV:', err);
           // Fallback to original blob if conversion fails
-          onRecordingComplete?.(webmBlob, recordedDuration);
+          if (sessionRef.current === thisSession) {
+            onRecordingComplete?.(webmBlob, recordedDuration);
+          }
         }
       };
 
@@ -162,10 +189,12 @@ export function useAudioRecording({
       setError(errorMessage);
       setIsRecording(false);
     }
-  }, [maxDurationSeconds, onRecordingComplete]);
+  }, [maxDurationSeconds, onRecordingComplete, platform.metadata.isTauri]);
 
   const stopRecording = useCallback(() => {
-    if (mediaRecorderRef.current && isRecording) {
+    // Check the ref rather than the `isRecording` state so this works even
+    // if React hasn't flushed the state update yet (e.g. rapid UI clicks).
+    if (mediaRecorderRef.current && mediaRecorderRef.current.state !== 'inactive') {
       mediaRecorderRef.current.stop();
       setIsRecording(false);
 
@@ -174,13 +203,18 @@ export function useAudioRecording({
         timerRef.current = null;
       }
     }
-  }, [isRecording]);
+  }, []);
 
   const cancelRecording = useCallback(() => {
     if (mediaRecorderRef.current) {
       cancelledRef.current = true; // Must be set before stop() triggers onstop
       chunksRef.current = [];
-      mediaRecorderRef.current.stop();
+      if (mediaRecorderRef.current.state !== 'inactive') {
+        mediaRecorderRef.current.stop();
+      }
+      // Clear immediately so onstop (if it fires synchronously on some
+      // browsers) doesn't see a stale ref.
+      mediaRecorderRef.current = null;
       setIsRecording(false);
       setDuration(0);
     }

backend/database/migrations.py

@@ -43,11 +43,14 @@ def run_migrations(engine) -> None:
     _migrate_generation_versions(engine, inspector, tables)
     _migrate_capture_settings(engine, inspector, tables)
     _migrate_mcp_bindings(engine, inspector, tables)
+    _migrate_profile_samples(engine, inspector, tables)
     _normalize_storage_paths(engine, tables)
+    _add_performance_indexes(engine, tables)
 
 
 # -- helpers ---------------------------------------------------------------
 
+
 def _get_columns(inspector, table: str) -> set[str]:
     return {col["name"] for col in inspector.get_columns(table)}
 
@@ -62,6 +65,7 @@ def _add_column(engine, table: str, column_sql: str, label: str) -> None:
 
 # -- per-table migrations --------------------------------------------------
 
+
 def _migrate_story_items(engine, inspector, tables: set[str]) -> None:
     if "story_items" not in tables:
         return
@@ -73,15 +77,15 @@ def _migrate_story_items(engine, inspector, tables: set[str]) -> None:
         logger.info("Migrating story_items: removing position column, using start_time_ms")
         with engine.connect() as conn:
             if "start_time_ms" not in columns:
-                conn.execute(text(
-                    "ALTER TABLE story_items ADD COLUMN start_time_ms INTEGER DEFAULT 0"
-                ))
-                result = conn.execute(text("""
+                conn.execute(text("ALTER TABLE story_items ADD COLUMN start_time_ms INTEGER DEFAULT 0"))
+                result = conn.execute(
+                    text("""
                     SELECT si.id, si.story_id, si.position, g.duration
                     FROM story_items si
                     JOIN generations g ON si.generation_id = g.id
                     ORDER BY si.story_id, si.position
-                """))
+                """)
+                )
                 current_story_id = None
                 current_time_ms = 0
                 for item_id, story_id, _position, duration in result.fetchall():
@@ -96,7 +100,8 @@ def _migrate_story_items(engine, inspector, tables: set[str]) -> None:
                 conn.commit()
 
             # Recreate table without the position column (SQLite lacks DROP COLUMN)
-            conn.execute(text("""
+            conn.execute(
+                text("""
                 CREATE TABLE story_items_new (
                     id VARCHAR PRIMARY KEY,
                     story_id VARCHAR NOT NULL,
@@ -110,13 +115,16 @@ def _migrate_story_items(engine, inspector, tables: set[str]) -> None:
                     FOREIGN KEY (story_id) REFERENCES stories(id),
                     FOREIGN KEY (generation_id) REFERENCES generations(id)
                 )
-            """))
-            conn.execute(text("""
+            """)
+            )
+            conn.execute(
+                text("""
                 INSERT INTO story_items_new (id, story_id, generation_id, start_time_ms, track, trim_start_ms, trim_end_ms, version_id, created_at)
                 SELECT id, story_id, generation_id, start_time_ms,
                     COALESCE(track, 0), COALESCE(trim_start_ms, 0), COALESCE(trim_end_ms, 0), version_id, created_at
                 FROM story_items
-            """))
+            """)
+            )
             conn.execute(text("DROP TABLE story_items"))
             conn.execute(text("ALTER TABLE story_items_new RENAME TO story_items"))
             conn.commit()
@@ -292,13 +300,55 @@ def _supports_drop_column(engine) -> bool:
     return tuple(int(p) for p in sqlite3.sqlite_version.split(".")[:3]) >= (3, 35, 0)
 
 
+def _migrate_profile_samples(engine, inspector, tables: set[str]) -> None:
+    if "profile_samples" not in tables:
+        return
+    columns = _get_columns(inspector, "profile_samples")
+    if "sort_order" not in columns:
+        _add_column(engine, "profile_samples", "sort_order INTEGER NOT NULL DEFAULT 0", "sort_order")
+        with engine.connect() as conn:
+            conn.execute(
+                text("CREATE INDEX IF NOT EXISTS ix_profile_samples_sort_order ON profile_samples (sort_order)")
+            )
+            conn.commit()
+
+
+def _add_performance_indexes(engine, tables: set[str]) -> None:
+    """Add query-performance indexes that were missing from the initial schema.
+
+    Each CREATE INDEX is wrapped in IF NOT EXISTS so this is safe to call on
+    every startup against both new and existing databases.
+    """
+    indexes = [
+        # History page: filter/sort by profile, status, created_at
+        ("generations", "ix_generations_profile_id", "profile_id"),
+        ("generations", "ix_generations_status", "status"),
+        ("generations", "ix_generations_created_at", "created_at"),
+        ("generations", "ix_generations_is_favorited", "is_favorited"),
+        # Version lookups per generation
+        ("generation_versions", "ix_generation_versions_generation_id", "generation_id"),
+        # Story item lookups per story
+        ("story_items", "ix_story_items_story_id", "story_id"),
+        # Capture list sorted by date
+        ("captures", "ix_captures_created_at", "created_at"),
+        # Sample lookups per profile
+        ("profile_samples", "ix_profile_samples_profile_id", "profile_id"),
+    ]
+    with engine.connect() as conn:
+        for table, index_name, column in indexes:
+            if table not in tables:
+                continue
+            conn.execute(text(f"CREATE INDEX IF NOT EXISTS {index_name} ON {table} ({column})"))
+        conn.commit()
+
+
 def _normalize_storage_paths(engine, tables: set[str]) -> None:
     """Normalize stored file paths to be relative to the configured data dir."""
     from pathlib import Path
 
-    from ..config import get_data_dir, to_storage_path, resolve_storage_path
+    from ..config import get_data_dir, resolve_storage_path, to_storage_path
 
-    data_dir = get_data_dir()
+    get_data_dir()
 
     path_columns = [
         ("generations", "audio_path"),
@@ -312,9 +362,7 @@ def _normalize_storage_paths(engine, tables: set[str]) -> None:
         for table, column in path_columns:
             if table not in tables:
                 continue
-            rows = conn.execute(
-                text(f"SELECT id, {column} FROM {table} WHERE {column} IS NOT NULL")
-            ).fetchall()
+            rows = conn.execute(text(f"SELECT id, {column} FROM {table} WHERE {column} IS NOT NULL")).fetchall()
             for row_id, path_val in rows:
                 if not path_val:
                     continue