Fixes #4963, #5064. FileDialog nav fixes & TableView redesign - #5062

… develop

Fixes text input controls to ignore Alt/Ctrl-modified keys, even with AssociatedText (Kitty protocol). Updates FileDialog TableView height. Adds regression tests for input handling and hotkey routing. Documents FileDialog keyboard/nav issues. Refactors KeyboardEventTests for clarity.

Improve FileDialog navigation and TableView key handling

- Reset TableView viewport X and Y to 0 on navigation for consistent top-left alignment in FileDialog.
- Enable TabStop on _tableViewContainer for better keyboard accessibility.
- Adjust _tableView height and anchor _tbFind Y position for improved layout robustness.
- Refactor TableView key handling: ignore control/modified keys, handle navigation only when focused and rows exist, and return true when a key is handled.

Replaces OnActivated with OnActivating, updating the method to return a bool based on ToggleCurrentCellSelection. This supports cancellable or conditional activation in line with new event handling conventions.

Comprehensive tests for TableView navigation, selection, events, and edge cases. Ensures current behavior is preserved ahead of planned redesign.

Refactored TableView to use TableSelection/TableSelectionRegion for richer selection state, replacing Point-based selection. Renamed EnsureSelectedCellIsVisible to EnsureCursorIsVisible and updated all references. Changed Command.Toggle to Command.ToggleExtend for extended selection. Improved null handling for Table and selection state, preventing NullReferenceExceptions. Updated tests and documentation to match the new model. Made minor code style and naming improvements.

Replaced all usages of SelectedRow/SelectedColumn with the new Value property and its Cursor.X/Y members for improved selection state management and null-safety. Updated event handlers to use ValueChanged instead of SelectedCellChanged, and replaced direct selection assignments with SetSelection calls. Modernized UI control initialization, streamlined menu/status bar construction, and improved code style and null handling throughout. Marked SelectedCellChanged as obsolete and updated tests and scenarios to use the new selection APIs.

No code modifications were present in the provided diff. No commit necessary.

Renamed the TableView event and event args from SelectedCellChanged/SelectedCellChangedEventArgs to CursorChanged/CursorChangedEventArgs. Updated all references, event invocations, and tests accordingly. Improved comments to clarify the event tracks cursor position changes, not cell selection.

Major overhaul of TableView selection and event model:
- Remove obsolete events (CellActivated, CellToggled, CursorChanged) and related args.
- All selection state now managed via Value (TableSelection).
- Internal selection fields are private; use SetSelection/Value APIs.
- Update all code/tests to use Value.Cursor and ValueChanged.
- Accept/Accepted replaces CellActivated; ToggleExtend handled directly.
- Deep-copy multi-selection regions for immutability.
- Refactor navigation, selection, and rendering to new model.
- Update all scenarios and tests for new APIs.
- Modernize code style and remove redundant code.

Improved and expanded XML documentation and in-code comments for TableView and related sources, fixing typos and grammar for accuracy and consistency. Major updates to tableview.md add a detailed table of contents, expanded sections, code examples, and event usage. Minor code fixes and improved parameter tags enhance maintainability and developer experience.

Refactored TableView.Selection.cs to move IValue<TableSelection?> implementation to the end of the file and organize related properties. Changed TableSelectionRegion to use init-only properties for immutability. Updated selection region logic to use immutable instances, improved region clamping, and fixed minor logic issues. Enhanced code style and maintainability without altering selection behavior.

Refactor TableView internals and API to use "cursor" instead of "selected"/"selection" for navigation state. Update all related fields, methods, comments, and tests for clarity and consistency. No functional changes; improves code readability and aligns with TableSelection.Cursor semantics.

Reorganize TableView by moving content-related properties and methods (content size, scrolling, viewport management) into TableView.Content.cs. This structural refactor improves code organization, separation of concerns, and maintainability. No functional changes introduced.

Comprehensive TableView API overhaul for v2.0.0: unified selection types, IValue<TableSelection?> support, navigation API terminology shift from "Selection" to "Cursor", and legacy API deprecation. Fixes keyboard selection toggling and region calculation bugs. Extracts content/viewport logic to a partial class and updates XML/docs. Ctrl+Click toggle regression noted for follow-up.

…minal.Gui into Issue-4963-filedialog

…i into Issue-4963-filedialog

Removes FILEDIALOG_ENABLE_TREE conditional blocks, making the directory tree, toggle button, and related styles always active in FileDialog. Updates FileDialogStyle and tests to support the unified implementation. FileDialogExamples now sets PreserveFilenameOnDirectoryChanges via checkbox. Tree functionality is now a standard, always-on part of the dialog UI.

- Add ".lnk" color mapping to FileSystemColorProvider
- Refine FileDialog pane border and alignment
- Reorder _treeView initialization for clarity
- Simplify TableView style for a cleaner appearance
- Use theme-based colors in TableView for consistency
- Ensure column color getter and style order are correct
- Set AllowsMultipleSelection to false in FileDialog
- Refactor ColumnStyle.Visible to use auto-property and MaxWidth logic