Add type-to-find search on the project workspace list

[kirillmitrofanov]

Summary

• Replaces the native Project Workspace <select> with a Chakra 2 searchable combobox (chakra-react-select@5) so users can type to find a project by name, description, or public/private.
• Menu shows the full name, a visibility badge, and a one-line description; the control stays clearable (same as choosing the empty placeholder today).
• No backend or visibility-rule changes. HPC Target select is unchanged.

Test plan

• pnpm test in gui/workflow_frontend (projectFilter unit tests)
• After a frontend deploy: open Project Workspace, type fMRI (or another mid-name fragment) and confirm the list filters
• Type a description fragment that is not in the name and confirm a match
• Type private / public and confirm visibility filtering
• Clear the selection and confirm the canvas unloads (existing handleProjectChange(null) path)
• Select a project from the filtered list and confirm flow load still works
• Live dbrain.jp still serves the old native select until this PR is deployed — do not treat it as verification of this change