Introduces Input Processing and Interaction helpers for the Ncurses renderer, ensuring robust mouse support and simplified event handling.
**Renderer (`renderers/ncurses`):**
- **`Clay_Ncurses_ProcessInput`**: Added a dedicated input processing function that handles both keyboard and mouse events.
- Implemented persistent `_isMouseDown` state tracking to fix missed "fast clicks" and preserve button state during drag operations.
- Adjusted `mousemask` to `BUTTON1_PRESSED | BUTTON1_RELEASED | REPORT_MOUSE_POSITION` to bypass Ncurses' internal click resolution delay.
- **`Clay_Ncurses_OnClick`**: Added a helper function to easily attach click listeners.
- Registers the user's callback directly via `Clay_OnHover` (avoiding allocation/proxies).
- Matches the standard Clay callback signature pattern.
**Example (`examples/ncurses-example`):**
- **Input Loop**: Migrated main loop to use `Clay_Ncurses_ProcessInput`.
- **Interactions**:
- Added a "Toggle Help" button to the sidebar.
- Implemented `HandleHelpToggleClick` callback, which explicitly checks for `CLAY_POINTER_DATA_RELEASED_THIS_FRAME` to validate clicks.
- Added visual hover effects to sidebar items.
**Documentation (`renderers/ncurses/README.md`):**
- Updated "Usage" section to demonstrate `Clay_Ncurses_ProcessInput`.
- Added "Input & Interaction" section documenting the new helpers.
