fix(typst): resolve all overlapping-token errors via @precedence

Lezer's buildTokenGroups rejects grammars with ambiguous token sets.
Eight overlaps existed:

  EscapeChar vs spaces       — EscapeChar { _ } matches \t; after '\'
                               it must win over the @skip spaces token.
  "(" / "." vs text tokens   — in the LALR-merged state after #CodeIdent,
                               callSuffix delimiters must beat
                               MarkupContent / StrongText / EmphText.
  "]" vs LineCommentContent  — inside #[...], the ContentBlock closer
                               must win even if it follows "//".

One extended @precedence declaration resolves all eight.

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

services/web/frontend/js/features/source-editor/lezer-typst/typst.grammar

@@ -207,8 +207,14 @@ Escape { "\\" EscapeChar }
   // Newline item — kept out of @skip so heading detection works.
   Newline { "\n" }
 
-  // Resolve ambiguities: longer/more-specific tokens win.
-  @precedence { CodeKeyword CodeBool CodeIdent }
+  // Resolve ambiguities: more-specific tokens win over broader catch-alls.
+  // EscapeChar > spaces: after '\', EscapeChar must win over the skip token
+  //   (both match \t; without this, '\t' would be mis-tokenized).
+  // "(" > "." > text tokens: after '#' CodeIdent, callSuffix delimiters must win
+  //   over MarkupContent/StrongText/EmphText in the LALR-merged state.
+  // "]" > LineCommentContent: inside #[...], ']' closes the ContentBlock even
+  //   if it appears after '//' (comment does not "protect" the bracket).
+  @precedence { CodeKeyword CodeBool CodeIdent EscapeChar "(" "." "]" spaces MarkupContent StrongText EmphText LineCommentContent }
 }
 
 @skip { spaces }