feat(client): Add SQLite file extension registration

[Copilot]

• Add addSqliteFileType function in src/filetypes.ts with extensions: .sqlite, .sqlite3, .db, .db3, .s3db, .sl3
• Import addSqliteFileType in src/index.ts
• Register SQLite file type in the activateArrowGrid function
• Add SQLite file type to the factory's fileTypes and defaultFor arrays
• Run biome formatter to ensure code style consistency
• Add SQLite icon support with light (sqlite.svg) and dark (sqlite_dark.svg) theme variants
• Import and use getSqliteIcon function in icon registration
• Add jp-icon-selectable class to SQLite icon paths for proper selection highlighting
• Run security check with CodeQL - No vulnerabilities found

Implementation Summary

Successfully added complete SQLite file extension support on the client side with full icon support for both light and dark themes. The implementation follows the same pattern as other file formats (Parquet, Avro, IPC, ORC).

Changes in Latest Commit

• Added class="jp-icon-selectable" to all path elements in sqlite.svg and sqlite_dark.svg
• This enables JupyterLab to change icon color when SQLite files are selected in the file browser, matching behavior of other file type icons (Avro, Parquet, ORC, Arrow IPC)

Security Summary

CodeQL analysis found no security vulnerabilities in the changes.

Original prompt

Add a new file extension for sqlite on the client side.
The server side is already done and does not need adjustments.
The protocol from the client must need not be updated.
This is only about registering the file, similarily to how parquet is register.
Look in the python code file_format.py to know which file extensions we support for sqlite.

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[AntoinePrv]

@copilot I have pushed a commit with the file icons sqlite.svg for light and sqlite_dark.svg for dark

[Copilot]

@copilot I have pushed a commit with the file icons sqlite.svg for light and sqlite_dark.svg for dark

Added icon support in commit 926dd3f. SQLite files now display with theme-appropriate icons (light/dark variants).

[AntoinePrv]

@copilot For the other files (say avro), when selected in the browser it turn all white without having a dedicated icon. How does it do that?

[Copilot]

@copilot For the other files (say avro), when selected in the browser it turn all white without having a dedicated icon. How does it do that?

The jp-icon-selectable CSS class enables JupyterLab to change the icon fill color when selected. Added this class to all path elements in both SQLite icon variants in commit d938c11. The icons will now turn white/change color when selected, matching the behavior of Avro, Parquet, ORC, and Arrow IPC files.