feat(keybinding): several shortcuts per action, mouse buttons, searchable picker

Shortcuts were defined in four places that drifted apart: per-action IPC channel
pairs, a hand-written VK table in the service, a second one in the renderer, and
three copies of the keycap styling. Adding an action meant editing all of them,
so two shortcuts stayed hardcoded in bootstrap and one had no settings entry at
all.

packages/core/src/keybinding.ts is now the single source for the binding type,
the selectable key catalog, the action catalog, normalization, validation,
conflict detection, display labels, search and deserialization. Main, preload
and renderer all read from it; nothing redefines keys or rules locally.

- Each action holds a list of bindings instead of one. AppConfig's four
  *Shortcut fields collapse into a single keyBindings map, migrated on launch.
- Mouse buttons can be bound. Left click is refused, right/middle need a
  modifier, side buttons are free. uiohook cannot swallow events, so the
  original click still fires and the UI says so.
- Keys can be picked from a grouped dropdown with a search box, not only by
  recording a keypress.
- HOTKEY's 14 channels become KEYBINDING's 9, taking the action as a parameter,
  so actions no longer multiply channels. The history and command popups moved
  out of bootstrap into ordinary actions.
- displayLabel is gone; labels derive from the binding and follow the app
  language and platform.

Fixes found on the way:
- Double-press hands-free was unreachable: lookup returned only the first
  matching action, and dictation shares its default binding.
- Reserved-combination checks compared joined key names, so a different modifier
  order let Ctrl+C through.
- Disabling shortcuts released every global registration in the process,
  including the popup ones, and never restored them.
- Enabling shortcuts after starting disabled left nothing registered.
- The dashboard stored the caption event payload instead of the state in it.

packages/i18n/src/locales/de.json

@@ -270,5 +270,60 @@
   "mobile.works.historyDescription": "Transkripte von Aufnahmen und Importen suchen und verwalten.",
   "mobile.meetings.templateEmpty": "Keine Meeting-Dokumentvorlagen verfügbar. Sie können das Meeting ohne Vorlage starten.",
   "mobile.meetings.templateNone": "Ohne Vorlage starten",
-  "mobile.meetings.templateNoneDesc": "Vorlage später bei der Dokumenterzeugung wählen"
+  "mobile.meetings.templateNoneDesc": "Vorlage später bei der Dokumenterzeugung wählen",
+  "keybinding.mouse.left": "Linke Maustaste",
+  "keybinding.mouse.right": "Rechte Maustaste",
+  "keybinding.mouse.middle": "Mittlere Maustaste",
+  "keybinding.mouse.back": "Maustaste Zurück",
+  "keybinding.mouse.forward": "Maustaste Vorwärts",
+  "keybinding.group.mouse": "Maus",
+  "keybinding.group.modifier": "Modifikatortasten",
+  "keybinding.group.function": "Funktionstasten",
+  "keybinding.group.letter": "Buchstaben",
+  "keybinding.group.digit": "Ziffern",
+  "keybinding.group.numpad": "Ziffernblock",
+  "keybinding.group.navigation": "Navigation",
+  "keybinding.group.editing": "Bearbeiten",
+  "keybinding.group.punctuation": "Sonderzeichen",
+  "keybinding.group.system": "System",
+  "keybinding.action.dictation": "Diktat",
+  "keybinding.action.dictation.desc": "Nimmt auf, solange die Taste gedrückt bleibt.",
+  "keybinding.action.handsFree": "Ein-Tasten-Modus",
+  "keybinding.action.handsFree.desc": "Zweimal drücken zum Umschalten.",
+  "keybinding.action.command": "Sprachbefehle",
+  "keybinding.action.command.desc": "Führt einen Befehl per Sprache aus.",
+  "keybinding.action.caption": "Live-Untertitel",
+  "keybinding.action.caption.desc": "Schaltet Live-Untertitel ein oder aus.",
+  "keybinding.action.historyPopup": "Verlaufs-Popup",
+  "keybinding.action.historyPopup.desc": "Öffnet das Verlaufs-Popup.",
+  "keybinding.action.commandPopup": "Befehls-Popup",
+  "keybinding.action.commandPopup.desc": "Öffnet das Befehls-Popup.",
+  "keybinding.reject.unknownKey": "Diese Taste wird nicht unterstützt",
+  "keybinding.reject.systemReserved": "Dies ist ein vom System reserviertes Tastenkürzel",
+  "keybinding.reject.modifierRequired": "Muss mit einer Modifikatortaste (Strg/Alt/Umschalt) kombiniert werden",
+  "keybinding.disabled.mouseLeft": "Der Linksklick wird für jede Bildschirmbedienung gebraucht und lässt sich nicht belegen",
+  "keybinding.warning.mousePassthrough": "Maustasten führen zusätzlich weiterhin ihre ursprüngliche Aktion aus",
+  "keybinding.ui.add": "Hinzufügen",
+  "keybinding.ui.remove": "Löschen",
+  "keybinding.ui.reset": "Auf Standard zurücksetzen",
+  "keybinding.ui.tabRecord": "Taste drücken",
+  "keybinding.ui.tabList": "Aus Liste wählen",
+  "keybinding.ui.search": "Tasten suchen",
+  "keybinding.ui.searchEmpty": "Keine Suchergebnisse",
+  "keybinding.ui.pressKeys": "Drücken Sie die gewünschte Taste oder Maustaste",
+  "keybinding.ui.noBindings": "Kein Tastenkürzel festgelegt",
+  "keybinding.ui.conflictWith": "Überschneidet sich mit {{action}}",
+  "keybinding.ui.modifiers": "Modifikatortasten",
+  "keybinding.ui.selectedKey": "Ausgewählte Taste",
+  "keybinding.ui.sectionVoice": "Sprache",
+  "keybinding.ui.sectionWindow": "Fenster / Popups",
+  "keybinding.ui.duplicate": "Dieses Tastenkürzel wurde bereits hinzugefügt",
+  "keybinding.ui.holdMode": "Halten",
+  "keybinding.ui.doublePress": "Doppeldruck",
+  "keybinding.ui.pickerTitle": "Tastenkürzel einrichten",
+  "keybinding.ui.pressToRecord": "Drücken, um die Aufnahme zu starten",
+  "keybinding.ui.recordHint": "Gib eine Kombination (z. B. Ctrl+Shift+Q) oder eine einzelne Taste (z. B. F5) ein",
+  "keybinding.ui.recordAgain": "Erneut eingeben",
+  "keybinding.ui.saveFailed": "Das Tastenkürzel konnte nicht gespeichert werden",
+  "keybinding.ui.globalEnabled": "Globale Tastenkürzel aktivieren"
 }