docs(editor): fix duplicated paragraph from dev merge resolution

The 'dev' merge into this branch left two redundant descriptions of the
completion provider in Section 2 (one from #84, one from #85). Collapsed into a
single accurate paragraph: registerSQLCompletionProvider -> registerCompletion
ItemProvider('sql', …) with trigger characters '.' and space, registered from
QueryEditor.tsx. Verified triggerCharacters ['.', ' '] at sql-completions.ts:121.

Author: cevheri

docs/editor/sql-alias-completion.md

@@ -84,13 +84,10 @@ Lightweight regex-based SQL parser that extracts table aliases without external
 
 #### 2. Completion Provider (`src/lib/editor/sql-completions.ts`)
 
-Monaco Editor completion provider (`registerCompletionItemProvider('sql', …)`, triggered on `.` and
-space) that integrates with the alias extractor. Registered by the editor and hosted in
-`src/components/QueryEditor.tsx`.
-Monaco Editor completion provider that integrates with the alias extractor. The
-provider is implemented as `registerSQLCompletionProvider(monaco, schemaCompletionCache)`
-and registered from `src/components/QueryEditor.tsx` (in an `useEffect` that returns the
-disposable for cleanup).
+Monaco Editor completion provider that integrates with the alias extractor. It is implemented as
+`registerSQLCompletionProvider(monaco, schemaCompletionCache)`, which calls
+`registerCompletionItemProvider('sql', …)` with trigger characters `.` and space. It is registered
+from `src/components/QueryEditor.tsx` in a `useEffect` that returns the disposable for cleanup.
 
 **Dot-triggered completion flow:**
 ```