[Feature Request] Editable path bar with autocomplete in Workspace files sidebar

Feature Request

Add an editable path bar with smart autocomplete to the Workspace files sidebar, allowing users to navigate directories by typing paths directly instead of relying solely on mouse clicks.

Motivation

Currently, the Workspace files sidebar only supports navigation via mouse interactions:

• Click the > arrow on a directory to enter it
• Click Up / Root buttons to go back

This is tedious when working with deeply nested project structures (e.g., ./projects/vcp-mate/src/components). Users have no way to jump directly to a specific path.

Proposed Solution

1. Editable Path Input

Replace the static path display with an <input> field:

• Type a path and press Enter to jump directly to that directory
• Input value syncs automatically when navigating via clicks

2. Smart Autocomplete Dropdown

Two complementary modes:

Filter mode (while typing)

• ./projects/vcp → lists ./projects/ entries filtered by vcp*
• docker → lists current directory entries filtered by docker*

Focus-directory mode (on click/focus)

• When the input shows a complete directory path like ./projects/HY-World-2.0
• On focus, automatically detect it is a directory and list its contents (src/, docs/, etc.)

3. Keyboard & Mouse Support

4. IME Support

Handle CJK input method composition correctly.

Related

• PR: #2215 (implementation)
• Related bug fix: #2206 (long filename overflow)

Start by reviewing PR #2215, which is identified as the implementation for this request, and compare it with related bug fix #2206. Done means the Workspace files sidebar has an editable path input, filtered and focus-directory autocomplete, keyboard and mouse selection, synchronized navigation, and correct IME composition handling.