feat: replace grouped autocomplete with flat list and type badge

Switch wiki-link autocomplete from BlockNote's default grouped suggestion
menu to a custom flat list sorted by relevance. Each item shows the note
type (with its accent color) discretely on the right side. Reduce
MAX_RESULTS from 20 to 10 for a cleaner, more focused list.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/utils/wikilinkSuggestions.test.ts

@@ -77,8 +77,8 @@ describe('constants', () => {
     expect(MIN_QUERY_LENGTH).toBe(2)
   })
 
-  it('MAX_RESULTS is 20', () => {
-    expect(MAX_RESULTS).toBe(20)
+  it('MAX_RESULTS is 10', () => {
+    expect(MAX_RESULTS).toBe(10)
   })
 })
 

src/utils/wikilinkSuggestions.ts

@@ -1,5 +1,5 @@
 export const MIN_QUERY_LENGTH = 2
-export const MAX_RESULTS = 20
+export const MAX_RESULTS = 10
 
 export interface WikilinkBaseItem {
   title: string