fix(web): support absolute paths in Open Project dialog

[tisDDM]

Summary

Fixes #9795

Allows the "Open project" dialog to browse and search directories
outside the user's home folder.

Changes

Server endpoint (file.ts)

• Added directory parameter to /find/file endpoint

File search (index.ts)

• File.search() now accepts an optional directory parameter
• Scans the specified directory directly when provided

Dialog component (dialog-select-directory.tsx)

• Parses absolute paths from user input
• Trailing slash (/develop/) shows directory contents
• Without trailing slash (/develop) searches parent for match
• Shows full path for directories outside home, ~ prefix for home paths

Testing

• /develop/ → lists folders in /develop/
• /develop/s → filters to folders starting with "s"
• d → searches home directory as before

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

Potential Duplicates Found

1. fix(app): allow browsing absolute paths on Windows (fix(app): allow browsing absolute paths on Windows #6624)

   • fix(app): allow browsing absolute paths on Windows #6624
   • Likely related: Both involve allowing absolute path browsing in project dialogs, though this one is Windows-specific

2. feat: improve directory search with path completion and subdirectory listing (feat: improve directory search with path completion and subdirectory listing #6940)

   • feat: improve directory search with path completion and subdirectory listing #6940
   • Likely related: Addresses similar directory search functionality and path handling features

These PRs appear to address overlapping or related functionality around path browsing and directory selection in the Open Project dialog.