feat(notifications): add notification history panel and overlay UX fixes

- New toggleNotificationHistory (Ctrl+N) session-scoped history panel; slides in from same edge as notification stack
- Overlay error/recovery toast follows notifications.overlayPosition; stack and history side seeded at startup
- Cold managed background startup initializes tray and visible overlay shell before tokenization warmups finish
- Add Update button to overlay update-available notifications
- Fix Ctrl+S sentence-card flow: only Anki progress notification, no duplicate status toast
- Fix overlay notification close/actions clickability above subtitle bars on Linux
- Increase pause-until-ready default timeout from 15s to 30s

plugin/subminer/options.lua

@@ -34,7 +34,7 @@ function M.load(options_lib, default_socket_path)
 		auto_start_visible_overlay = false,
 		auto_start_pause_until_ready = true,
 		auto_start_pause_until_ready_owns_initial_pause = false,
-		auto_start_pause_until_ready_timeout_seconds = 15,
+		auto_start_pause_until_ready_timeout_seconds = 30,
 		osd_messages = true,
 		log_level = "info",
 		aniskip_enabled = false,

plugin/subminer/process.lua

@@ -6,7 +6,7 @@ local OVERLAY_RESTART_PING_RETRY_DELAY_SECONDS = 0.2
 local OVERLAY_RESTART_PING_MAX_ATTEMPTS = 20
 local AUTO_PLAY_READY_LOADING_OSD = "Loading subtitle tokenization..."
 local AUTO_PLAY_READY_READY_OSD = "Subtitle tokenization ready"
-local DEFAULT_AUTO_PLAY_READY_TIMEOUT_SECONDS = 15
+local DEFAULT_AUTO_PLAY_READY_TIMEOUT_SECONDS = 30
 local DUPLICATE_VISIBLE_OVERLAY_TOGGLE_SECONDS = 0.25
 
 function M.create(ctx)

plugin/subminer/session_bindings.lua

@@ -244,6 +244,8 @@ function M.create(ctx)
 			return { "--toggle-secondary-sub" }
 		elseif action_id == "toggleSubtitleSidebar" then
 			return { "--toggle-subtitle-sidebar" }
+		elseif action_id == "toggleNotificationHistory" then
+			return { "--session-action", '{"actionId":"toggleNotificationHistory"}' }
 		elseif action_id == "markAudioCard" then
 			return { "--mark-audio-card" }
 		elseif action_id == "markWatched" then