Correct batches through bulk editing and participant review

[Andesha]

Parent

#192

What to build

Let users select recordings and bulk-assign participant, session, task, and run values while preserving individual exceptions. For noncanonical datasets, let the user explicitly map filename or relative-path tokens to manifest fields, preview the extracted values and affected recordings, and confirm the mapping before it changes assignments. Provide a separate participant review surface for demographics and linked-recording counts. Prevent accidental near-duplicate participant identities, and propagate deliberate participant renames across the batch.

Mappings are user-owned structure, not semantic inference: the application must not guess what tokens such as subj018 or SS1 mean, or silently strip prefixes. Any token selection, delimiter/pattern, field meaning, or transformation must be explicitly configured or confirmed by the user.

Acceptance criteria

• Selected recordings can receive fixed participant/session/task/run assignments in one action.
• Users can define a filename or relative-path token mapping to participant, session, task, or run.
• A mapping previews extracted values, transformations, and all affected recordings before application.
• Applying a confirmed mapping creates explicit assignments without relying on later inference or mapping reruns.
• A user can correct an individual recording after a bulk assignment or mapping without changing the rest of the selection.
• Participants can be created through assignment and recordings can be linked to them explicitly.
• Participant demographics are reviewed separately from recording metadata.
• Each participant exposes its linked-recording count and recordings remain traceable from that participant.
• Renaming a participant updates every linked recording.
• The UI warns or prevents near-duplicate participant IDs such as equivalent prefixed and unprefixed forms.
• Automated coverage verifies fixed bulk changes, token mappings and previews, individual exceptions, participant linkage, and rename propagation.

Blocked by

• Ticket 1 — Build a manually populated batch workbench.

[Andesha]

Implemented on the umbrella branch in draft PR #200. This will land with the remaining #192 sub-issues. Outstanding umbrella-branch CI cleanup will be handled before the draft PR is finalized.