D5.2 Freeze weekend: DTC courses cutover and self-paced mode

Plan issue D5.2, phase 5 of the community-base unification plan.

Spec: docs/plan/phase-5.md, section D5.2, in DataTalksClub/community-base. Status is tracked in docs/plan/STATUS.md there, which stays the source of truth.

Depends on: D5.1. Do not start until every one of them is done in STATUS.md.

Freeze issue. Playbook P13 applies: this moves data during a scheduled weekend freeze of the site. Do not start it outside a planned freeze window.

Process

This repository's AGENTS.md and _docs/PROCESS.md govern this work, with _docs/specs/ as the product authority. The plan says what to build and how to verify it; the site process says how work is done here.

Spec

Repository: DataTalksClub/website. Depends on: D5.1. Freeze required: yes. Playbook P13 on the development environment. Checks: cohort page, homework submission, leaderboard,
project peer review, certificate download, one self-paced course created in Studio with a unit
visible to a registered member.

Done when

• spec 04 updated: the package owns curriculum and coursework; DTC keeps LearnerProfile
  and route compatibility

Read docs/plan/phase-5.md section D5.2, docs/plan/STATUS.md, AGENTS.md, and _docs/PROCESS.md; confirm D5.1 is done before scheduling the P13 freeze. Use the listed cohort, homework, leaderboard, peer review, certificate, and self-paced checks, then update spec 04 so the stated ownership and compatibility criteria are met.