feat(ui): land the centralized shortcuts core from #2532 with review fixes

The schema/config/bindings/registry/dispatcher module, useKeybind hooks,
recording dialog, reworked shortcuts settings page, help dialog, and the
localized action labels — re-based onto current main rather than merged
(the branch predates 440+ commits including the session-tabs shortcuts).

Review fixes applied on top of the original:
- close_session_tab (alt+w) joins the schema with labels in every locale;
  it shipped on main after the PR's base and would otherwise silently die.
- switch_context_surface's special-case in conflict resolution is now a
  declared prefixStyle config property instead of a magic id string.
- Duplicate handler registration warns in dev builds.
- The risky-browser-shortcut warning inspects every chord and covers
  mod+q/d/h/j/o/u plus mod+shift+w/q.
- The dispatcher remembers which target armed a two-chord prefix so the
  window-level completion handler can distinguish a deliberate sequence
  from typing in an editable field (guard lands with the dispatch hook).
- Schema tests: unique normalized default bindings enforced, and the
  flat-file-era override format proven to keep resolving.

packages/ui/src/lib/i18n/messages/es.settings.ts

@@ -1101,7 +1101,7 @@ export const settingsDict = {
   "settings.openchamber.keyboardShortcuts.overwritePrompt": "Esta combinación ya está usada por otro atajo. ¿Sobrescribir y limpiar esa otra asignación?",
   "settings.openchamber.keyboardShortcuts.field.pressKeys": "Pulsa las teclas...",
   "settings.openchamber.keyboardShortcuts.error.captureFirst": "Captura un atajo primero.",
-  "settings.openchamber.keyboardShortcuts.warning.riskyBrowserShortcut": "Este atajo puede entrar en conflicto con los predeterminados del navegador. Todavía se guarda.",
+    "settings.openchamber.keyboardShortcuts.warning.riskyBrowserShortcut": "Este atajo puede entrar en conflicto con los predeterminados del navegador. Aun así, puedes guardarlo.",
   "settings.openchamber.keyboardShortcuts.action.open_go_to_line.label": "Ir a línea (editor de archivos)",
   "settings.openchamber.keyboardShortcuts.action.open_command_palette.label": "Abrir paleta de comandos",
   "settings.openchamber.keyboardShortcuts.action.focus_input.label": "Enfocar entrada",
@@ -1116,6 +1116,7 @@ export const settingsDict = {
   "settings.openchamber.keyboardShortcuts.action.switch_context_surface.label": "Cambiar superficie del panel de contexto",
   "settings.openchamber.keyboardShortcuts.action.switch_context_surface.suffix": " + 1…0",
   "settings.openchamber.keyboardShortcuts.action.new_chat.label": "Nueva sesión",
+  "settings.openchamber.keyboardShortcuts.action.close_session_tab.label": "Cerrar pestaña de sesión",
   "settings.openchamber.keyboardShortcuts.action.new_chat_worktree.label": "Nuevo borrador de worktree",
   "settings.openchamber.keyboardShortcuts.action.new_mini_chat.label": "Nueva ventana Mini Chat",
   "settings.openchamber.keyboardShortcuts.action.open_help.label": "Abrir atajos de teclado",
@@ -1130,6 +1131,27 @@ export const settingsDict = {
   "settings.openchamber.keyboardShortcuts.action.expand_input.label": "Expandir entrada",
   "settings.openchamber.keyboardShortcuts.action.open_timeline_dialog.label": "Abrir línea de tiempo de conversación",
   "settings.openchamber.keyboardShortcuts.action.toggle_prompt_navigator.label": "Mostrar u ocultar navegador de prompts",
+  "settings.openchamber.keyboardShortcuts.warning.contextualPrefix": "Esta secuencia comparte un prefijo contextual con {action}. Cuando su contexto está activo, esa acción tiene prioridad.",
+  "settings.openchamber.keyboardShortcuts.category.session": "Controles de sesión",
+  "settings.openchamber.keyboardShortcuts.category.models": "Modelos y agentes",
+  "settings.openchamber.keyboardShortcuts.category.panels": "Paneles y herramientas",
+  "settings.openchamber.keyboardShortcuts.category.navigation": "Navegación",
+  "settings.openchamber.keyboardShortcuts.category.application": "Aplicación",
+  "settings.openchamber.keyboardShortcuts.actions.edit": "Editar",
+  "settings.openchamber.keyboardShortcuts.actions.confirm": "Confirmar",
+  "settings.openchamber.keyboardShortcuts.dialog.title": "Editar {action}",
+  "settings.openchamber.keyboardShortcuts.dialog.instructions": "Pulse hasta dos combinaciones de teclas, con un máximo de tres teclas cada una. Tras la primera, espere hasta 3 segundos por una segunda combinación. Use Confirmar para aplicar o Cancelar para descartar. Retroceso elimina la última.",
+  "settings.openchamber.keyboardShortcuts.dialog.firstChord": "Primera combinación",
+  "settings.openchamber.keyboardShortcuts.dialog.secondChord": "Segunda combinación",
+  "settings.openchamber.keyboardShortcuts.dialog.recording": "Pulse las teclas…",
+  "settings.openchamber.keyboardShortcuts.unassigned": "Sin asignar",
+  "settings.openchamber.keyboardShortcuts.error.prefixConflict": "Esto entra en conflicto con la secuencia usada por {action}. Elija otra combinación.",
+  "settings.openchamber.keyboardShortcuts.error.exactConflict": "Esta combinación ya la usa {action}.",
+  "settings.openchamber.keyboardShortcuts.error.internalConflict": "Esta combinación entra en conflicto con un atajo integrado, que no se puede reemplazar.",
+  "settings.openchamber.keyboardShortcuts.action.open_draft_project_picker.label": "Abrir selector de proyecto de borrador",
+  "settings.openchamber.keyboardShortcuts.action.open_draft_worktree_picker.label": "Abrir selector de árbol de trabajo de borrador",
+  "settings.openchamber.keyboardShortcuts.action.open_session_list.label": "Abrir sesiones recientes",
+  "settings.openchamber.keyboardShortcuts.action.toggle_dictation.label": "Entrada de voz",
   "settings.projects.sidebar.total": "Total {count}",
   "settings.projects.sidebar.actions.addProject": "Añadir proyecto",
   "settings.projects.page.empty.noProjects": "No hay proyectos disponibles.",