fix(11-02): repair broken text strings from mass CSS variable replacement

The mass find-and-replace incorrectly replaced the word 'surface' in
human-readable text strings and type literals, not just CSS class contexts.
Fixed: App.tsx control surface text, DocumentCenter knowledge base text,
i18n en.ts, and Panel tone prop type literal.

src/renderer/i18n/en.ts

@@ -745,7 +745,7 @@ export const en: Record<string, string> = {
   "ops.newMeeting": "New meeting",
   "ops.newSprint": "New sprint",
   "ops.deleteDocument": "Delete document",
-  "ops.deleteDocumentMsg": "This removes the document from the company knowledge bg-card border border-border shadow-sm.",
+  "ops.deleteDocumentMsg": "This removes the document from the company knowledge base.",
   "ops.deleteKnowledgeEntry": "Delete knowledge entry",
   "ops.deleteKnowledgeMsg": "This removes the entry from the shared company knowledge base.",
   "ops.deleteMeeting": "Delete meeting",