Fix L46/L71/L74: unify yt-dlp missing message, editable dir inputs, swatch a11y

L46: Introduced YTDLP_MISSING_MSG constant in binaries.ts. All four callers
     (download, indexer, probe, ytdlp) now emit the same user-facing string:
     "yt-dlp.exe is missing. Open Settings -> Software update to re-download it."
     This removes newline-embedded messages and four divergent phrasings.

L71: Removed readOnly from videoDir/audioDir folder inputs in SettingsView.
     Added onChange handler so users can paste or type a path directly without
     being forced to use the Browse button. The path still flows through
     applySettings() in main, which validates it.

L74: Accent color swatches were triple-labeled (aria-pressed + aria-label +
     title). Replaced with a single aria-label that embeds "(selected)" state,
     plus title for the hover tooltip. Removed the incorrect aria-pressed
     (these are selection buttons, not toggles).

typecheck + 242 tests green.

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

src/main/binaries.ts

@@ -80,6 +80,10 @@ export function getFfprobePath(): string {
   return join(getBinDir(), 'ffprobe.exe')
 }
 
+/** User-facing error shown whenever yt-dlp.exe is not found at startup. */
+export const YTDLP_MISSING_MSG =
+  'yt-dlp.exe is missing. Open Settings → Software update to re-download it.'
+
 /** Optional bundled external downloader; absent unless dropped into resources/bin. */
 export function getAria2cPath(): string {
   return join(getBinDir(), 'aria2c.exe')

src/main/download.ts

@@ -10,7 +10,8 @@ import {
   getFfmpegPath,
   getFfprobePath,
   getSystem32Path,
-  getAppIconImage
+  getAppIconImage,
+  YTDLP_MISSING_MSG
 } from './binaries'
 import { getSettings, getDownloadArchivePath, getDefaultMediaDir } from './settings'
 import { ensureManagedYtdlp } from './ytdlp'
@@ -225,7 +226,7 @@ export function startDownload(wc: WebContents, opts: StartDownloadOptions): Star
   if (!existsSync(ytdlp)) {
     return {
       ok: false,
-      error: `yt-dlp.exe is missing and couldn't be restored from the bundle.\nReinstall AeroFetch, or drop yt-dlp.exe into resources/bin/ (see the README there).`
+      error: YTDLP_MISSING_MSG
     }
   }
   // ffmpeg is used by nearly every download (merge, audio extract, thumbnail/

src/main/indexer.ts

@@ -11,7 +11,7 @@
 
 import { execFile } from 'child_process'
 import { existsSync } from 'fs'
-import { getYtdlpPath } from './binaries'
+import { getYtdlpPath, YTDLP_MISSING_MSG } from './binaries'
 import { cleanError } from './log'
 import { assertHttpUrl } from './url'
 import {
@@ -90,7 +90,7 @@ export async function indexSource(
     return { ok: false, error: (e as Error).message }
   }
   if (!existsSync(getYtdlpPath())) {
-    return { ok: false, error: 'yt-dlp.exe not found. Drop it into resources/bin/.' }
+    return { ok: false, error: YTDLP_MISSING_MSG }
   }
 
   const cls = classifySource(url)

src/main/probe.ts

@@ -1,6 +1,6 @@
 import { execFile } from 'child_process'
 import { existsSync } from 'fs'
-import { getYtdlpPath } from './binaries'
+import { getYtdlpPath, YTDLP_MISSING_MSG } from './binaries'
 import { fmtBytes } from './lib/formatters'
 import { cleanError } from './log'
 import { assertHttpUrl } from './url'
@@ -115,7 +115,7 @@ export function probeMedia(url: string): Promise<ProbeResult> {
   if (!existsSync(ytdlp)) {
     return Promise.resolve({
       ok: false,
-      error: `yt-dlp.exe not found at ${ytdlp}\nDrop it into resources/bin/ (see the README there).`
+      error: YTDLP_MISSING_MSG
     })
   }
   let target: string

src/main/ytdlp.ts

@@ -1,7 +1,7 @@
 import { execFile } from 'child_process'
 import { existsSync, mkdirSync, copyFileSync } from 'fs'
 import { dirname } from 'path'
-import { getYtdlpPath, getBundledYtdlpPath } from './binaries'
+import { getYtdlpPath, getBundledYtdlpPath, YTDLP_MISSING_MSG } from './binaries'
 import { getSettings, setSettings } from './settings'
 import { shouldAutoCheckYtdlp } from './ytdlpPolicy'
 import {
@@ -39,7 +39,7 @@ export function getYtdlpVersion(): Promise<YtdlpVersionResult> {
   if (!existsSync(ytdlpPath)) {
     return Promise.resolve({
       ok: false,
-      error: `yt-dlp.exe not found at ${ytdlpPath}\nDownload it into resources/bin/ (see the README there).`
+      error: YTDLP_MISSING_MSG
     })
   }
 
@@ -85,7 +85,7 @@ export function updateYtdlp(channel: YtdlpUpdateChannel): Promise<YtdlpUpdateRes
   if (!existsSync(ytdlpPath)) {
     return Promise.resolve({
       ok: false,
-      error: `yt-dlp.exe not found at ${ytdlpPath}\nDownload it into resources/bin/ (see the README there).`
+      error: YTDLP_MISSING_MSG
     })
   }