feat(ext/popup): wire Document type into form + detail + list dispatchers

Document is no longer 'coming soon' — the type chooser unlocks it,
form dispatcher routes to documentType.renderForm, detail dispatcher
routes to documentType.renderDetail. teardown chains include documentType.

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

extension/src/popup/components/item-list.ts

@@ -233,7 +233,7 @@ const NEW_TYPE_OPTIONS: Array<{ type: ItemType; icon: string; label: string; dis
   { type: 'card',        icon: '💳', label: 'card' },
   { type: 'key',         icon: '🗝',  label: 'key' },
   { type: 'totp',        icon: '⏱',  label: 'totp' },
-  { type: 'document',    icon: '📄', label: 'document', disabled: true, tooltip: 'coming in γ — needs attachment upload' },
+  { type: 'document',    icon: '📄', label: 'document' },
 ];
 
 function showNewTypePicker(anchor: HTMLElement): void {