Improve startup dictionary progress and fix overlay/plugin input handlin

- show a dedicated startup OSD "building" phase for character dictionary sync
- forward bare `Tab` from visible overlay to mpv so AniSkip works while focused
- fix Windows plugin env override resolution for `SUBMINER_BINARY_PATH`

backlog/tasks/task-146 - Forward-overlay-Tab-to-mpv-for-AniSkip.md

@@ -0,0 +1,66 @@
+---
+id: TASK-146
+title: Forward overlay Tab to mpv for AniSkip
+status: Done
+assignee:
+  - codex
+created_date: '2026-03-09 00:00'
+updated_date: '2026-03-09 00:00'
+labels:
+  - bug
+  - overlay
+  - aniskip
+  - linux
+dependencies: []
+---
+
+## Description
+
+<!-- SECTION:DESCRIPTION:BEGIN -->
+
+Fix visible-overlay keyboard handling so bare `Tab` is forwarded to mpv instead of being consumed by Electron focus navigation. This restores the default AniSkip `TAB` binding while the overlay has focus, especially on Linux.
+
+<!-- SECTION:DESCRIPTION:END -->
+
+## Acceptance Criteria
+
+<!-- AC:BEGIN -->
+
+- [x] #1 Visible overlay forwards bare `Tab` to mpv as `keypress TAB`.
+- [x] #2 Modal overlays keep their existing local `Tab` behavior.
+- [x] #3 Automated regression coverage exists for the input handler and overlay factory wiring.
+<!-- AC:END -->
+
+## Implementation Plan
+
+<!-- SECTION:PLAN:BEGIN -->
+
+1. Add a failing regression around visible-overlay `before-input-event` handling for bare `Tab`.
+2. Add/extend overlay factory tests so the new mpv-forward callback is wired through runtime construction.
+3. Patch overlay input handling to intercept visible-overlay `Tab` and send mpv `keypress TAB`.
+4. Run focused overlay tests, typecheck, and changelog validation.
+<!-- SECTION:PLAN:END -->
+
+## Implementation Notes
+
+<!-- SECTION:NOTES:BEGIN -->
+
+Extracted visible-overlay input handling into `src/core/services/overlay-window-input.ts` so the `Tab` forwarding decision can be unit tested without loading Electron window primitives.
+
+Visible overlay `before-input-event` now intercepts bare `Tab`, prevents the browser default, and forwards mpv `keypress TAB` through the existing mpv runtime command path. Modal overlays remain unchanged.
+
+Verification:
+
+- `bun test src/core/services/overlay-window.test.ts src/main/runtime/overlay-window-factory.test.ts src/main/runtime/overlay-window-factory-main-deps.test.ts src/main/runtime/overlay-window-runtime-handlers.test.ts`
+- `bun x tsc --noEmit`
+<!-- SECTION:NOTES:END -->
+
+## Final Summary
+
+<!-- SECTION:FINAL_SUMMARY:BEGIN -->
+
+Visible overlay focus no longer blocks the default AniSkip `Tab` binding. Bare `Tab` is now forwarded straight to mpv while the visible overlay is active, and modal overlays still retain their own normal focus behavior.
+
+Added regression coverage for both the input-routing decision and the runtime plumbing that carries the new mpv forwarder into overlay window creation.
+
+<!-- SECTION:FINAL_SUMMARY:END -->