chore(backlog): maintain task backlog and add changelog fragments

- Move completed tasks (85, 117, 118, 155) to backlog/completed/
- Delete superseded task files (166 verification, 172 drilldown)
- Add stats dashboard milestone m-1
- Add new tasks (190, 194)
- Update task metadata across remaining backlog items
- Add changelog fragments for stats, mpv args, and subtitle filtering

backlog/tasks/task-125 - Add-native-AI-API-key-secret-storage.md

@@ -4,6 +4,7 @@ title: Add native AI API key secret storage
 status: To Do
 assignee: []
 created_date: '2026-03-08 07:25'
+updated_date: '2026-03-18 05:27'
 labels:
   - ai
   - config
@@ -17,20 +18,17 @@ references:
     /Users/sudacode/projects/japanese/SubMiner/src/core/services/jellyfin-token-store.ts
   - /Users/sudacode/projects/japanese/SubMiner/src/main.ts
 priority: medium
+ordinal: 2000
 ---
 
 ## Description
 
 <!-- SECTION:DESCRIPTION:BEGIN -->
-
 Store the shared AI provider API key using the app's native secret-storage pattern so users do not need to keep the OpenRouter key in config files or shell commands.
-
 <!-- SECTION:DESCRIPTION:END -->
 
 ## Acceptance Criteria
-
 <!-- AC:BEGIN -->
-
 - [ ] #1 Users can configure the shared AI provider without storing the API key in config.jsonc.
 - [ ] #2 The app persists and reloads the shared AI API key using encrypted native secret storage when available.
 - [ ] #3 Behavior is defined for existing ai.apiKey and ai.apiKeyCommand configs, including compatibility during migration.