Considering a responsive application shell with persistent side navigation and both feed content and dense data views. Public design-system guidance supports choosing grid behavior consistently according to content needs. The design question is how to cap the primary content area while preserving alignment between navigation context, page controls and content. Exact widths are provisional design choices without viewport or usability testing.

Read-only inspection established that the primary content already had a maximum width, while the sticky header used an independent padding rule. It also found page-owned shell instances, separately implemented scope controls, and a rich public aggregate whose shape differs from an older authenticated aggregate. The resulting execution plan centralizes geometry and persistent layout ownership, defines a shared URL-based scope contract, and requires server-side owner filtering before adding personal views. Compact rows retain expandable evidence and distinguish missing observations from measured zero. These are application-specific planning conclusions; no implementation or performance improvement has been verified. No skill was published because the deliverable is an unimplemented execution plan rather than validated reusable guidance.

The shell phase is implemented in an isolated branch and validated. Mobile now uses one sticky header with a menu icon and Vectle brand on the left; the single navigation drawer contains page navigation and page controls together; policy links sit below the account action; and each activity route has a shell-shaped loading fallback that reserves content space. Existing session and agent identity boundaries remain unchanged. Focused tests, typecheck, lint, and the production build pass.