[Epic]: Post-release PLATE marketplace publication tasks

GitHub Milestones are the canonical Epic container. This is a stub Epic for the human-owned publication work that should happen after the marketplace install-surface features are merged and a release has been cut.

Desired outcome

The post-release human publication and launch work for the PLATE Copilot CLI marketplace path is tracked separately from Epic #377, so Epic #377 can close once its feature work lands and the release ceremony proceeds.

Scope and boundaries

In scope

• Human-owned package publication for plate-core
• Human-owned declaration/publication of akasper/plate as the supported public marketplace path
• Lightweight follow-through after the release containing the marketplace feature work is cut

Out of scope for this stub

• Repository implementation work for the marketplace install surface
• Blocking the closure of Epic #377 once its feature work is merged
• Reworking the release ceremony for the feature Epic itself

Success criteria

• Human-owned publication tasks are tracked independently of Epic #377
• #380, #625, and #626 inherit this Epic milestone instead of (or in addition to) the feature Epic milestone
• The Epic can be worked after the release containing the marketplace feature work is cut

Expected child features / Tasks

• #380 — Task: Publish plate-core package for marketplace runtime
• #625 — Task: Configure PyPI trusted publisher for plate-core automated releases (publish-pypi.yml)
• #626 — Task: Perform initial PyPI back-publish of plate-core v0.7.2 (and prior tags) via the new workflow
• #381 — Task: Publish public Copilot CLI marketplace entry for PLATE

Risks, assumptions, and dependencies

• This Epic is intentionally Task-only (human real-world actions that the AI partner cannot perform).
• It follows the release of the feature work from Epic #377 rather than blocking that Epics close-out.
• These Tasks formalize the "in the real world" human steps (external account/credential setup, manual initial publishes) that were identified during the PyPI automation work (#623 / #624).

Start with child issues #380, #625, #626, and #381; read the publish-pypi.yml workflow in #625 and the release dependency described here. Completion means the human-owned plate-core publication, trusted-publisher setup, back-publish, and public marketplace entry are tracked and performed after the relevant release.