[marksftw]

The sidebar now keeps task controls and layout consistent across computers, including tasks on a computer that is not currently selected.

Changes:

• When viewing "Connections" in the side bar, the triangle was on the left of the computer icon. Moved it to the right and put it behind a hover state like the other headers.
• Made the spacing between projects consistent when expanded, collapsed, or empty.
• For long titles, fade the truncated part instead of ending with ellipses.
• Hide Archive when it has no tasks, while keeping bounded prefetch, pagination and retry actions accessible.

Validation:

• Formatting and all-targets app Clippy passed in the pinned macOS environment.
• Added focused regressions for inactive-computer controls before selection, duplicate task IDs, preserved drafts/selection, visible delete confirmation, and stale owner/account/grant results.
• Existing project-spacing and archive/pagination regressions are retained.
• GitHub CI passed on this head: agent-lint, agent-test, agent-macos, agent-windows and ci-ok.

Stack: layer 1 of 2, based on current master. #1213 adds the activity indicators above this cleanup.