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

tests/attach.bats

@@ -5,6 +5,7 @@ REPO=$(cd "$(dirname "$BATS_TEST_FILENAME")/.." && pwd)
 
 setup() {
     TMP=$(mktemp -d /tmp/devdesk-test.XXXXXX) # short path: unix socket limit
+    unset DEVDESK_REMOTE_CONTROL CLAUDE_ARGS DEVDESK_SESSION TMUX TMUX_PANE # when run from inside DevDesk
     export DEVDESK_ENV=/dev/null
     export DEVDESK_PROJECTS_ROOT="$TMP/projects"
     export DEVDESK_STATE_DIR="$TMP/state"
@@ -200,6 +201,17 @@ claude_args() {
     [ "$(jq -r '.sessions[] | select(.name=="alpha") | .context.model' <<<"$output")" = Opus ]
 }
 
+@test "statusline footer shows plan use on a subscription and dollars only on API billing" {
+    sub='{"model":{"display_name":"Opus"},"context_window":{"used_percentage":10},
+      "cost":{"total_cost_usd":1186.99},"rate_limits":{"five_hour":{"used_percentage":8.4}}}'
+    run bash -c "echo '$sub' | '$REPO/libexec/devdesk-statusline'"
+    [[ $output == *"5h 8%"* ]]
+    [[ $output != *'$'* ]]
+    api='{"model":{"display_name":"Opus"},"context_window":{"used_percentage":10},"cost":{"total_cost_usd":1.5}}'
+    run bash -c "echo '$api' | '$REPO/libexec/devdesk-statusline'"
+    [[ $output == *'$1.5'* ]]
+}
+
 @test "hooks ignore Claude running in some other tmux server" {
     start_server
     other="$TMP/other.sock"