fix: v0.9.3 plan usage instead of API-price cost; larger footer

- Footer shows "5h N%" when Claude sends rate_limits (Pro/Max); the
  dollar figure is an API-price estimate, so it is kept only for API-key
  billing. Sessions tooltip follows suit. Closes #40
- Bottom row: 40px, larger hints, bold 1rem usage meters with wider bars;
  narrow windows drop hints instead of clipping the meters. Closes #41
- bats setup unsets inherited DevDesk env so tests pass inside DevDesk

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WHRLCCdXYm41Qx5kNhehaP

libexec/devdesk-statusline

@@ -43,13 +43,17 @@ if [[ $session =~ ^[A-Za-z0-9][A-Za-z0-9_-]{0,63}$ ]]; then
     fi
 fi
 
-# Footer line: session · model · context % · cost. ANSI colour numbers, not RGB,
-# so the browser's dark or light palette applies (devdesk#31).
+# Footer line: session · model · context % · plan use. ANSI colour numbers, not
+# RGB, so the browser's dark or light palette applies (devdesk#31). Claude sends
+# rate_limits only to Pro/Max subscribers; there .cost is an API-price estimate,
+# not a bill, so show the 5-hour plan use instead and keep $ for API-key billing.
 jq -rM --arg s "$session" '
     def c($sgr; $t): "\u001b[\($sgr)m\($t)\u001b[0m";
     def pct: if . == null then "—" else "\(. | floor)%" end;
     [ (if $s != "" then c("33"; "◈ \($s)") else empty end),
       c("36"; .model.display_name // "Claude"),
       c("37"; "ctx \(.context_window.used_percentage | pct)"),
-      c("37"; "$\((.cost.total_cost_usd // 0) * 100 | round / 100)")
+      (if .rate_limits.five_hour.used_percentage != null
+       then c("37"; "5h \(.rate_limits.five_hour.used_percentage | pct)")
+       else c("37"; "$\((.cost.total_cost_usd // 0) * 100 | round / 100)") end)
     ] | join(c("90"; " · "))' <<<"$input" 2>/dev/null || true