THALis: data collector repository extraction

collector moving out of the main repo. pin both versions with the session somehow, otherwise which frontend produced which analysis input??

archived change (f5ccae3): the React eeg-collector application is removed from the main repository and moved into a separate repository. The commit summary establishes the extraction but does not give a verified destination URL.

reproducibility consequence: a main-repository commit no longer fixes the collector implementation. Each experiment needs both the analysis/acquisition revision and the collector revision, plus the selected paradigm and cue configuration.

review questions: what protocol connects collector and EEG backend, and which exported file schema is expected by training? Can an older dataset be decoded after the collector changes? Record a schema/version identifier rather than relying only on a filename.

historical navigation: code paths from December/January remain valid only in their corresponding commits. Do not invent a current repository path or line number for components that were extracted.

archived code references: f5ccae3.

Virtual-hand collector interface