i18n: localize 3 placeholders that stayed in German under English

Three input placeholders in the HTML had hardcoded German strings that were never routed through the locale system:

- clipStartPart (Clip cutter modal — "Start Part-Nummer") said "z.B. 42" regardless of language
- clipUrl (Clips tab) read "...oder https://www.twitch.tv/..." with a mid-string German conjunction
- cutterFilePath (Video cutter "Datei ausgewahlt" field) read "Keine Datei ausgewahlt..." even under EN

Added three locale keys (clips.urlPlaceholder, clips.startPartPlaceholder, cutter.filePathPlaceholder) with DE+EN translations, plus the three setPlaceholder() wire-up calls in renderer-texts.ts. The HTML defaults stay German (consistent with the other placeholders) but the JS now overrides them when the user picks English (or re-renders when language changes).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/renderer-locale-de.ts

@@ -437,7 +437,9 @@ const UI_TEXT_DE = {
         formatTemplate: '(benutzerdefiniert)',
         templateEmpty: 'Das Template darf im benutzerdefinierten Modus nicht leer sein.',
         templatePlaceholder: '{date}_{part}.mp4',
-        templateHelp: 'Platzhalter: {title} {id} {channel} {date} {part} {part_padded} {trim_start} {trim_end} {trim_length} {date_custom="yyyy-MM-dd"}'
+        templateHelp: 'Platzhalter: {title} {id} {channel} {date} {part} {part_padded} {trim_start} {trim_end} {trim_length} {date_custom="yyyy-MM-dd"}',
+        urlPlaceholder: 'https://clips.twitch.tv/... oder https://www.twitch.tv/.../clip/...',
+        startPartPlaceholder: 'z.B. 42'
     },
     cutter: {
         videoInfoFailed: 'Konnte Video-Informationen nicht lesen. FFprobe installiert?',
@@ -452,7 +454,8 @@ const UI_TEXT_DE = {
         infoFps: 'FPS',
         infoSelection: 'Auswahl',
         startLabel: 'Start:',
-        endLabel: 'Ende:'
+        endLabel: 'Ende:',
+        filePathPlaceholder: 'Keine Datei ausgewaehlt...'
     },
     merge: {
         empty: 'Keine Videos ausgewahlt',

src/renderer-locale-en.ts

@@ -437,7 +437,9 @@ const UI_TEXT_EN = {
         formatTemplate: '(custom template)',
         templateEmpty: 'Template cannot be empty in custom template mode.',
         templatePlaceholder: '{date}_{part}.mp4',
-        templateHelp: 'Placeholders: {title} {id} {channel} {date} {part} {part_padded} {trim_start} {trim_end} {trim_length} {date_custom="yyyy-MM-dd"}'
+        templateHelp: 'Placeholders: {title} {id} {channel} {date} {part} {part_padded} {trim_start} {trim_end} {trim_length} {date_custom="yyyy-MM-dd"}',
+        urlPlaceholder: 'https://clips.twitch.tv/... or https://www.twitch.tv/.../clip/...',
+        startPartPlaceholder: 'e.g. 42'
     },
     cutter: {
         videoInfoFailed: 'Could not read video info. Is FFprobe installed?',
@@ -452,7 +454,8 @@ const UI_TEXT_EN = {
         infoFps: 'FPS',
         infoSelection: 'Selection',
         startLabel: 'Start:',
-        endLabel: 'End:'
+        endLabel: 'End:',
+        filePathPlaceholder: 'No file selected...'
     },
     merge: {
         empty: 'No videos selected',

src/renderer-texts.ts

@@ -110,6 +110,9 @@ function applyLanguageToStaticUI(): void {
     setText('clipDialogPartHint', UI_TEXT.clips.dialogPartHint);
     setText('clipDialogFormatLabel', UI_TEXT.clips.dialogFormatLabel);
     setText('clipDialogConfirmBtn', UI_TEXT.clips.dialogConfirm);
+    setPlaceholder('clipUrl', UI_TEXT.clips.urlPlaceholder);
+    setPlaceholder('clipStartPart', UI_TEXT.clips.startPartPlaceholder);
+    setPlaceholder('cutterFilePath', UI_TEXT.cutter.filePathPlaceholder);
     setText('cutterSelectTitle', UI_TEXT.static.cutterSelectTitle);
     setText('cutterBrowseBtn', UI_TEXT.static.cutterBrowse);
     setText('cutterInfoDurationLabel', UI_TEXT.cutter.infoDuration);