Add Mission Control dashboard

[TheGreatAxios]

Summary

• New /mission-control route (CL-6488/CL-6489) — the dashboard the owner's mock has and the app was missing. / stays the Myra land-hop redirect, untouched.
• Pinned above the sidebar's footer rail as its own row (per DESIGN.md's Shell & Navigation section), not a 7th button mixed into Routines/Files/Skills/Agents/Plugins/Insights.
• Panels and what backs them:
  • Stat strip (active runs, waiting on you, runs today, spend today) — real: working tasks + running routines, the needs-you count, and insights/activity.
  • Needs you — real GET .../approvals/needs-you list, with working Approve/Deny wired to the existing approveApproval/rejectApproval calls and the same cache invalidation the chat approval card uses. Empty state: "Nothing waiting on you."
  • In flight — real useBenchActivity working tasks (running/needs-you, not queued) plus running routine fires. Tokens are intentionally omitted — no honest per-run token count exists on this feed, so the column was dropped rather than showing a placeholder. Empty state: "Nothing running right now."
  • Jump back in — real recent workbenches/chats/agents, sorted by their own recency field; a bench with no recorded activity timestamp is left out rather than given an invented one. Empty state: "Nothing recent yet."
  • This week — real 7-day runs/spend off the same insights/activity fetch, linking to Insights.
• No unified cross-workbench "Evals" feed exists yet, so no Evals panel is on this page — nothing to fabricate there.
• Note: the brief mentioned @corbits/error-sink/reportError, but that package doesn't exist on main — action failures use the existing toast(...) convention (@corbits/react-ui) other pages already use instead.

Test plan

• bun test test/mission-control-page.test.tsx — row-derivation unit tests + a render test asserting the honest empty states
• bun test test/routes.test.tsx test/sidebar.test.tsx src/shell/sidebar-rows.test.ts — route table and nav/sidebar tests stay green
• bun test (apps/web) — 791 pass / 3 pre-existing unrelated failures (tailwind-build.test.ts needs a prior bun run build, not run in this environment)
• bunx tsc --noEmit (apps/web) — clean
• bun run scripts/checks/tailwind-source.ts — ok, no new @source entry needed