fix(cli): support physical delete and home/end navigation (#13265)

[maoxin1234]

Description

Fixes #13265.

In the \cn\ CLI prompt editor:

• Physical \Delete\ was previously routed to \deleteBackward()\ alongside \Backspace, causing forward deletion to behave as backward deletion.
• \Home\ and \End\ navigation keys were unhandled, and unparsed terminal escape sequences for line editing (\u001b[1~, \u001b[4~, \u001b[H, \u001b[F, \u001b[3~) were consumed without action.

Changes

1. Added \moveToLineStart()\ and \moveToLineEnd()\ on \TextBuffer.
2. Routed \key.delete\ to \ his.deleteForward()\ while preserving \key.backspace\ as \ his.deleteBackward().
3. Handled \key.home\ (move to current line start) and \key.end\ (move to current line end).
4. Recognized standard terminal escape sequences for Home, End, and forward Delete in \handleOptionKey.
5. Updated and expanded unit tests in \TextBuffer.test.ts.

Test Plan

• Ran \�un test extensions/cli/src/ui/TextBuffer.test.ts\ (all 79 tests passing).