feat(context): Interactive AST Tree Masking with per-symbol toggles

src/models.py

@@ -497,6 +497,7 @@ class FileItem:
  force_full: bool = False
  ast_signatures: bool = False
  ast_definitions: bool = False
+ ast_mask: dict[str, str] = field(default_factory=dict)
  injected_at: Optional[float] = None
 
  def to_dict(self) -> Dict[str, Any]:
@@ -509,6 +510,7 @@ class FileItem:
    "force_full": self.force_full,
    "ast_signatures": self.ast_signatures,
    "ast_definitions": self.ast_definitions,
+   "ast_mask": self.ast_mask,
    "injected_at": self.injected_at,
   }
 
@@ -523,6 +525,7 @@ class FileItem:
    force_full=data.get("force_full", False),
    ast_signatures=data.get("ast_signatures", False),
    ast_definitions=data.get("ast_definitions", False),
+   ast_mask=data.get("ast_mask", {}),
    injected_at=data.get("injected_at"),
   )