Enhance Go/Shell semantic analysis and add ContextBuilder

- Upgrade `GoParser` to use tree-sitter-go for deep extraction (structs, methods, complexity).
- Upgrade `ShellParser` to use tree-sitter-bash for function, variable, and command extraction.
- Implement `ContextBuilder` for token-aware context assembly with compression strategies.
- Update `GoSemanticSnapshotBuilder` and `ShellSemanticSnapshotBuilder` to populate new metadata.
- Add tree-sitter queries in `resources/queries/`.
- Add unit tests for parsers and context builder.

Author: google-labs-jules[bot]

codesage/analyzers/ast_models.py

@@ -9,10 +9,18 @@ class ASTNode(BaseModel):
     # A generic property to hold things like operator/operand values
     value: Any = None
 
+class VariableNode(ASTNode):
+    name: str
+    value: Optional[str] = None
+    kind: str = "global"  # global, local, field (for structs)
+    type_name: Optional[str] = None # For typed variables (Go)
+    is_exported: bool = False
+
 class FunctionNode(ASTNode):
     name: str
     params: List[str] = []
     return_type: Optional[str] = None
+    receiver: Optional[str] = None # For Go methods
     is_async: bool = False
     decorators: List[str] = []
     complexity: int = 1
@@ -23,14 +31,18 @@ class FunctionNode(ASTNode):
 class ClassNode(ASTNode):
     name: str
     methods: List[FunctionNode] = []
+    fields: List[VariableNode] = [] # For structs
+    base_classes: List[str] = []
 
 class ImportNode(ASTNode):
     path: str
+    alias: Optional[str] = None
 
 class FileAST(BaseModel):
     path: str
     functions: List[FunctionNode] = []
-    classes: List[ClassNode] = []
+    classes: List[ClassNode] = [] # Classes, Structs, Interfaces
+    variables: List[VariableNode] = []
     imports: List[ImportNode] = []
     # The root of the raw AST tree
     tree: Optional[ASTNode] = None