Per-container healthcheck history

Clicking a day-cell on the dashboard's 7-day health widget, or a project's health strip on the projects list, now opens a detail page showing each container's health state for that specific day, grouped by project in the org-wide view.
From there, a "View full history" link switches into a period view: a stacked bar chart of container counts per health state over time (7, 14, 30, or 90 days), for the whole organization or scoped to a single project.

> Note: the single-day detail view and the 7/14/30/90-day period picker described above were replaced the same day, see v0.0.12-beta below.

The projects list "Health" column and the dashboard's 7-day widget previously only checked whether a container was running, ignoring Docker's own HEALTHCHECK status: a container that was running but failing its healthcheck showed as healthy there, while the project's "Containers" tab (which already combined both signals) correctly showed it degraded. All four surfaces (Containers tab, projects list, dashboard widget, and the new history page) now share one single health computation, so they can no longer disagree.

The project health strip on the projects list moved from a 14-day window to 7 days, to visually match the dashboard's 7-day widget.