Self-review: drop the formatter re-export shim, import @shared/format directly

The prior commit kept a pass-through `export { fmtBytes, fmtSpeed, fmtEta }` in
main/lib/formatters.ts purely so existing importers wouldn't have to change —
which re-exported fmtSpeed (zero importers, dead) and left download.ts re-
exporting fmtBytes/fmtEta with no consumer at all, undercutting the "one home"
goal.

Now the real consumers import from the canonical module directly:
- probe.ts and the download.test import from @shared/format.
- formatters.ts keeps only its internal `import { fmtBytes }` (for parseProgress)
  and no longer re-exports.
- download.ts re-exports only parseProgress (its own function); the dead
  fmtBytes/fmtEta re-export is removed.

No behavior change. typecheck + 248 tests + eslint + prettier green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/main/download.ts

@@ -80,9 +80,9 @@ export function hasActiveDownloads(): boolean {
 }
 
 // --- Formatting helpers (raw yt-dlp numbers → human strings) ----------------
-// Implementations live in lib/formatters.ts (no electron import chain) so they
+// parseProgress lives in lib/formatters.ts (no electron import chain) so it can
-// can be unit-tested in isolation (L37). Re-exported here for external callers.
+// be unit-tested in isolation (L37). Byte/ETA formatters live in @shared/format.
-export { fmtBytes, fmtEta, parseProgress } from './lib/formatters'
+export { parseProgress } from './lib/formatters'
 import { parseProgress } from './lib/formatters'
 
 function send(wc: WebContents, ev: DownloadEvent): void {

src/main/lib/formatters.ts

@@ -2,10 +2,9 @@ import type { DownloadProgress } from '@shared/ipc'
 import { fmtBytes } from '@shared/format'
 
 // yt-dlp progress-line parsing. Extracted from download.ts so it can be
-// unit-tested without pulling in the electron import chain (L37). The byte/
+// unit-tested without pulling in the electron import chain (L37). Byte/speed/ETA
-// speed/ETA formatters now live in @shared/format (one home for both sides of
+// formatting lives in @shared/format — the one home for both sides of the IPC
-// the IPC boundary); re-exported here so existing importers keep working.
+// boundary; consumers import it directly.
-export { fmtBytes, fmtSpeed, fmtEta } from '@shared/format'
 
 function num(s?: string): number | undefined {
   if (!s || s === 'NA') return undefined

src/main/probe.ts

@@ -1,7 +1,7 @@
 import { execFile } from 'child_process'
 import { existsSync } from 'fs'
 import { getYtdlpPath, YTDLP_MISSING_MSG } from './binaries'
-import { fmtBytes } from './lib/formatters'
+import { fmtBytes } from '@shared/format'
 import { cleanError } from './log'
 import { assertHttpUrl } from './url'
 import { entryUrl, fmtDuration, type RawEntry } from './indexerCore'

test/download.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect } from 'vitest'
-// Import from the pure formatter module directly — no electron import chain (L37).
+// Import from the pure modules directly — no electron import chain (L37).
-import { fmtBytes, fmtEta, parseProgress } from '../src/main/lib/formatters'
+import { parseProgress } from '../src/main/lib/formatters'
+import { fmtBytes, fmtEta } from '../src/shared/format'
 
 describe('fmtBytes', () => {
   it('formats bytes under 1 KB verbatim', () => {