Loki Mode

Dashboard fixes: sidebar rebalance, honest App Runner status, stable version

• Sidebar rebalance: the left sidebar is now clean navigation that breathes;
  the System Status panel + session controls move into a new COLLAPSIBLE right
  sidebar (remembered state; a 48px rail with a live connection dot when
  collapsed; a11y + responsive). This also fixes a real reachability bug where
  the tall status panel starved the left nav to ~88px, leaving only 2 of 16 tabs
  clickable - all 16 are now reachable.
• App Runner honest status: a skill/CLI-built app (no app-runner.json) was
  always reported "stopped" even while serving. The dashboard now probes the
  recorded port (real TCP connect, off the event loop) and reports running with
  the real URL ONLY when it genuinely answers - never fabricated; excludes the
  dashboard's own port and compose-owned detections; honest "stopped" when the
  port is not serving.
• Stable version display: the System Status version flipped between a stale
  per-project value (baked into a project's state file by whatever engine last
  built it) and the live version. All status paths now read the single live
  engine version, so it no longer flips.