feat: add resumability detection and pause warnings

- Update 'fetch_metadata' to detect 'Accept-Ranges' HTTP header
- Persist 'resumable' flag in DownloadItem across backend and frontend
- Add confirmation dialog when pausing non-resumable downloads (single and bulk actions)
- Improve UI for start/pause/options buttons by adopting the application accent color on hover

src/bindings/DownloadItem.ts

@@ -2,4 +2,4 @@
 import type { DownloadCategory } from "./DownloadCategory";
 import type { DownloadStatus } from "./DownloadStatus";
 
-export type DownloadItem = { id: string, url: string, fileName: string, status: DownloadStatus, fraction?: number, speed?: string, eta?: string, size?: string, category: DownloadCategory, dateAdded: string, connections?: number, speedLimit?: string, username?: string, password?: string, headers?: string, checksum?: string, cookies?: string, mirrors?: string, destination?: string, isMedia?: boolean, mediaFormatSelector?: string, queueId?: string, queuePosition?: number, hasBeenDispatched?: boolean, };
+export type DownloadItem = { id: string, url: string, fileName: string, status: DownloadStatus, fraction?: number, speed?: string, eta?: string, size?: string, category: DownloadCategory, dateAdded: string, resumable?: boolean, connections?: number, speedLimit?: string, username?: string, password?: string, headers?: string, checksum?: string, cookies?: string, mirrors?: string, destination?: string, isMedia?: boolean, mediaFormatSelector?: string, queueId?: string, queuePosition?: number, hasBeenDispatched?: boolean, };

src/bindings/MetadataResponse.ts

@@ -1,3 +1,3 @@
 // This file was generated by [ts-rs](https://github.com/Aleph-Alpha/ts-rs). Do not edit this file manually.
 
-export type MetadataResponse = { url: string, filename: string, size: string, size_bytes: number, };
+export type MetadataResponse = { url: string, filename: string, size: string, size_bytes: number, resumable: boolean, };

src/bindings/PersistedSettings.ts

@@ -8,4 +8,13 @@ import type { SettingsTab } from "./SettingsTab";
 import type { SiteLogin } from "./SiteLogin";
 import type { Theme } from "./Theme";
 
-export type PersistedSettings = { theme: Theme, baseDownloadFolder: string, categorySubfolders: { [key in string]: string }, categoryDirectoryOverrides: { [key in string]: string }, approvedDownloadRoots: Array<string>, maxConcurrentDownloads: number, globalSpeedLimit: string, isSidebarVisible: boolean, activeSettingsTab: SettingsTab, scheduler: SchedulerSettings, schedulerRunning: boolean, schedulerActiveDownloadIds: Array<string>, schedulerLastStartKey: string, schedulerLastStopKey: string, lastCustomSpeedLimitKiB: number, perServerConnections: number, maxAutomaticRetries: number, showNotifications: boolean, playCompletionSound: boolean, appFontSize: AppFontSize, listRowDensity: ListRowDensity, showDockBadge: boolean, showMenuBarIcon: boolean, proxyMode: ProxyMode, proxyHost: string, proxyPort: number, customUserAgent: string, askWhereToSaveEachFile: boolean, preventsSleepWhileDownloading: boolean, mediaCookieSource: MediaCookieSource, siteLogins: Array<SiteLogin>, extensionPairingToken: string, autoCheckUpdates: boolean, keychainAccessGranted: boolean, };
+export type PersistedSettings = { theme: Theme, baseDownloadFolder: string, categorySubfolders: { [key in string]: string }, categoryDirectoryOverrides: { [key in string]: string }, approvedDownloadRoots: Array<string>, maxConcurrentDownloads: number, globalSpeedLimit: string, isSidebarVisible: boolean, activeSettingsTab: SettingsTab, scheduler: SchedulerSettings, schedulerRunning: boolean, schedulerActiveDownloadIds: Array<string>, schedulerLastStartKey: string, schedulerLastStopKey: string, lastCustomSpeedLimitKiB: number, perServerConnections: number, maxAutomaticRetries: number, showNotifications: boolean, playCompletionSound: boolean, appFontSize: AppFontSize, listRowDensity: ListRowDensity, showDockBadge: boolean, showMenuBarIcon: boolean, proxyMode: ProxyMode, proxyHost: string, proxyPort: number, customUserAgent: string, askWhereToSaveEachFile: boolean, preventsSleepWhileDownloading: boolean, mediaCookieSource: MediaCookieSource, siteLogins: Array<SiteLogin>, 
+/**
+ * The HMAC shared secret for the browser extension.  It is persisted in the
+ * settings database so that startup never needs to touch the OS keychain.
+ * The keychain is still used as defence-in-depth — grant_keychain_access
+ * writes the token there — but the DB copy is the primary read path,
+ * eliminating the OS credential prompt that macOS shows when the binary
+ * signature changes after an update.
+ */
+extensionPairingToken: string, autoCheckUpdates: boolean, keychainAccessGranted: boolean, };