feat(torrents): harden lifecycle and web-seed management

- Enforce generation-safe seed admission and budget tracking.
- Make web-seed RPC, persistence, rollback, and startup attachment lifecycle-safe.
- Keep Torrent progress, DHT, seed-capacity, and web-seed validation covered.
- Ignore local TORRENT_FEATURES.md roadmap notes.

src/utils/downloadActions.ts

@@ -4,6 +4,7 @@ const STARTABLE_STATUSES: ReadonlySet<DownloadStatus> = new Set([
   'ready',
   'staged',
   'paused',
+  'waitingToSeed',
   'failed',
 ]);
 
@@ -12,6 +13,7 @@ const PAUSABLE_STATUSES: ReadonlySet<DownloadStatus> = new Set([
   'queued',
   'downloading',
   'seeding',
+  'waitingToSeed',
   'processing',
   'retrying',
 ]);
@@ -64,7 +66,7 @@ export const startActionLabel = (status: DownloadStatus): 'Start' | 'Resume' =>
   status === 'ready' || status === 'staged' || status === 'failed' ? 'Start' : 'Resume';
 
 export const isTransferLocked = (status: DownloadStatus): boolean =>
-  status === 'downloading' || status === 'processing' || status === 'seeding' || status === 'retrying';
+  status === 'downloading' || status === 'processing' || status === 'seeding' || status === 'waitingToSeed' || status === 'retrying';
 
 export const isIdentityLocked = (status: DownloadStatus): boolean =>
   isTransferLocked(status) || status === 'completed';

src/utils/downloads.ts

@@ -31,6 +31,7 @@ const ACTIVE_DOWNLOAD_STATUSES: ReadonlySet<DownloadStatus> = new Set([
   'downloading',
   'processing',
   'seeding',
+  'waitingToSeed',
   'retrying',
 ]);
 
@@ -70,6 +71,12 @@ export const MAX_TORRENT_TRACKER_INTERVAL = 604800;
 export const DEFAULT_TORRENT_MAX_OPEN_FILES = 100;
 export const MIN_TORRENT_MAX_OPEN_FILES = 1;
 export const MAX_TORRENT_MAX_OPEN_FILES = 4096;
+export const DEFAULT_TORRENT_DHT_MESSAGE_TIMEOUT = 10;
+export const MIN_TORRENT_DHT_MESSAGE_TIMEOUT = 1;
+export const MAX_TORRENT_DHT_MESSAGE_TIMEOUT = 600;
+export const DEFAULT_TORRENT_MAX_CONCURRENT_SEEDS = 2;
+export const MIN_TORRENT_MAX_CONCURRENT_SEEDS = 1;
+export const MAX_TORRENT_MAX_CONCURRENT_SEEDS = 64;
 
 const parseIntegerOption = (value: unknown): number | undefined => {
   if (typeof value === 'number') {
@@ -105,6 +112,24 @@ export const normalizeTorrentMaxOpenFiles = (value: unknown): number | undefined
     : undefined;
 };
 
+export const normalizeTorrentDhtMessageTimeout = (value: unknown): number | undefined => {
+  const parsed = parseIntegerOption(value);
+  return parsed !== undefined
+    && parsed >= MIN_TORRENT_DHT_MESSAGE_TIMEOUT
+    && parsed <= MAX_TORRENT_DHT_MESSAGE_TIMEOUT
+    ? parsed
+    : undefined;
+};
+
+export const normalizeTorrentMaxConcurrentSeeds = (value: unknown): number | undefined => {
+  const parsed = parseIntegerOption(value);
+  return parsed !== undefined
+    && parsed >= MIN_TORRENT_MAX_CONCURRENT_SEEDS
+    && parsed <= MAX_TORRENT_MAX_CONCURRENT_SEEDS
+    ? parsed
+    : undefined;
+};
+
 // Keep every filename component within the common cross-platform filesystem
 // limit. Count UTF-8 bytes because POSIX filesystems enforce bytes, while this
 // bound is also conservative for Windows filename components.