Task: Open sprint 30

Open sprint 30: scaffold it, wire it into the version and the agile index, bump the version to 0.0.30 and update vcpkg.

• Sprint 30 is the current sprint.
• The version is 0.0.30 everywhere the recipe names it.
• The vcpkg submodule is updated.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

Every number this task claims about a tree, with the command that produced it and the commit it was measured at. A number without both is not a measurement, because a clean-up record describes a tree and trunk moves under a branch: a consumer count, a gate's component count and a suite's size all change with no code changing, and the reader of a bare number cannot tell which tree it came from. Where the raw output matters, put it in an evidence/ file beside the task and name that file in the Command column.

Manual QA scenarios (scaffolded via compass add test_scenario) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Sprint 30 is open and is the current sprint. The project is on version 0.0.30, the readme and site point at the v0.0.29 screenshot, and vcpkg is on its latest tracked commit. No stories moved, because sprint 29's unfinished work is already in the product backlog. The mission is provisional: it takes the priority the sprint 29 release notes name.

The same branch makes a release carry its packages: a tag now builds the Linux package, and each platform attaches its packages to the GitHub release. The workflows upload by pattern, so a version bump no longer edits them, and the bump recipe says so.