Data: attach dyad_id and Prolific identifiers to every row

[htsukamoto5]

Phase 1 — unblocked. Needs the data-egress issue in place to be observable.

There is no jsPsych.data.addProperties() call anywhere in either experiment, so:

• No PROLIFIC_PID, STUDY_ID, or SESSION_ID is attached to any data row. Without these we cannot reconcile collected data against Prolific submissions or approve payments.
• No dyad identifier on data rows. This one is subtle and matters a lot: the entire analysis is dyad-level (reference shortening within a dyad across blocks), and nothing on a row currently says which two participants formed the pair. save_group: true on roleTrial gives a single group snapshot, and partner_id is in scope but never written into data.

Work

• Capture PROLIFIC_PID / STUDY_ID / SESSION_ID from URL params and attach via addProperties.
• Attach a stable dyad_id (the session/room id) to every row.
• Attach run config for provenance: BLOCKS / TRIALS, round_timeout, and the experiment file name — needed when piloting at different values.
• Capture viewport/browser. Relates to the mobile block in the Prolific-wrapper issue: a 6x2 tangram grid on a phone is a different task.

See READINESS.md section 3.