feat: Phase N power-user surface (terminal, palette, per-item, sort, url-templates)

- Built-in yt-dlp terminal: src/main/terminal.ts streams raw yt-dlp runs
  (binary fixed, gated on customCommandEnabled), new TerminalView + sidebar tab
- Command palette (Ctrl/Cmd+K), portal-free CommandPalette.tsx wired in App
- Per-playlist-item editing: per-row video/audio toggle + All video/All audio
  batch; addPlaylist enqueues via addMany with per-item kind
- Weighted format sorting: DownloadOptions.formatSort -> raw -S (overrides codec)
- URL-regex template auto-matching: CommandTemplate.urlPattern + selectExtraArgs
  matchesUrl, threaded through resolveExtraArgs; field in TemplateManager

typecheck + test (192) + electron-vite build all clean. Roadmap: Phase N COMPLETE.

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

src/main/buildArgs.ts

@@ -143,6 +143,7 @@ export function parseExtraArgs(raw: string): string[] {
  *
  *  - customCommandEnabled off               → [] (always)
  *  - perDownloadExtraArgs defined (even '')  → those args
+ *  - else a template whose urlPattern matches → that template's args (most specific)
  *  - else a matching defaultTemplateId       → that template's args
  *  - else                                    → []
  */
@@ -150,10 +151,20 @@ export function selectExtraArgs(params: {
   customCommandEnabled: boolean
   perDownloadExtraArgs: string | undefined
   defaultTemplateId: string | null
-  templates: Pick<CommandTemplate, 'id' | 'args'>[]
+  templates: Pick<CommandTemplate, 'id' | 'args' | 'urlPattern'>[]
+  /** the download URL, for urlPattern auto-matching */
+  url?: string
 }): string[] {
   if (!params.customCommandEnabled) return []
   if (params.perDownloadExtraArgs !== undefined) return parseExtraArgs(params.perDownloadExtraArgs)
+  // A template whose urlPattern matches this URL auto-applies, ahead of the global
+  // default — it's the more specific choice.
+  if (params.url) {
+    const matched = params.templates.find(
+      (t) => t.urlPattern && matchesUrl(t.urlPattern, params.url!)
+    )
+    if (matched) return parseExtraArgs(matched.args)
+  }
   if (params.defaultTemplateId) {
     const tpl = params.templates.find((t) => t.id === params.defaultTemplateId)
     if (tpl) return parseExtraArgs(tpl.args)
@@ -161,6 +172,15 @@ export function selectExtraArgs(params: {
   return []
 }
 
+/** Case-insensitive regex test of a template's urlPattern; a bad pattern never matches. */
+export function matchesUrl(pattern: string, url: string): boolean {
+  try {
+    return new RegExp(pattern, 'i').test(url)
+  } catch {
+    return false
+  }
+}
+
 /**
  * Parse a raw trim string (one or more time ranges, comma- or newline-separated)
  * into yt-dlp `--download-sections` specs. Each range is normalised to the
@@ -347,9 +367,13 @@ export function buildArgs(
     }
   } else {
     args.push('-f', videoSelector(opts), '--merge-output-format', o.videoContainer)
-    // Codec preference is a sort tiebreaker AFTER resolution/fps, so it nudges the
-    // pick toward the chosen codec without overriding the requested quality.
-    if (o.preferredVideoCodec !== 'any') {
+    // A raw format-sort string (advanced) wins outright; otherwise the codec
+    // preference is a sort tiebreaker AFTER resolution/fps, nudging the pick toward
+    // the chosen codec without overriding the requested quality.
+    const sort = o.formatSort.trim()
+    if (sort) {
+      args.push('-S', sort)
+    } else if (o.preferredVideoCodec !== 'any') {
       const token = o.preferredVideoCodec === 'av1' ? 'av01' : o.preferredVideoCodec
       args.push('-S', `res,fps,vcodec:${token}`)
     }