Remove vision tools (except take_screenshot) and macax tools

Vision tools removed:
- extract_text (OCR from image files)
- extract_text_with_boxes (OCR with bounding boxes)
- vision_find_text (find text in app windows)
- vision_click_text (find and click on text)
- vision_click_near_text (click near text labels)

macax tools removed:
- macax_list_apps
- macax_get_frontmost_app
- macax_activate_app
- macax_press_key
- macax_type_text

The LLM can now read images directly via read_image tool.
take_screenshot is retained for capturing application windows.

Files deleted:
- crates/g3-core/src/tools/vision.rs
- crates/g3-core/src/tools/macax.rs
- docs/macax-tools.md

Updated tool counts: 12 core + 15 webdriver = 27 total

crates/g3-core/src/tools/mod.rs

@@ -6,17 +6,13 @@
 //! - `file_ops` - File reading, writing, and editing
 //! - `todo` - TODO list management
 //! - `webdriver` - Browser automation via WebDriver
-//! - `macax` - macOS Accessibility API tools
-//! - `vision` - Vision-based text finding and clicking
 //! - `misc` - Other tools (screenshots, code search, etc.)
 
 pub mod executor;
 pub mod file_ops;
-pub mod macax;
 pub mod misc;
 pub mod shell;
 pub mod todo;
-pub mod vision;
 pub mod webdriver;
 
 pub use executor::ToolExecutor;