Add 5h rate limit bar and session cost to statusline

Dumps harness JSON to os.tmpdir() on each render to inspect available
fields. Adds a combined usage segment showing the Pro 5-hour rate limit
as a colour-coded bar and session cost in USD; each part is omitted
gracefully when its data is absent, so the script works for API instances too.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

custom_statusline.js

@@ -6,6 +6,8 @@
 'use strict';
 
 const { execSync } = require('child_process');
+const fs = require('fs');
+const path = require('path');
 const os = require('os');
 
 const R = '\x1b[0m';
@@ -25,6 +27,10 @@ process.stdin.on('end', () => {
   let data = {};
   try { if (input.trim()) data = JSON.parse(input); } catch (_) {}
 
+  try {
+    fs.writeFileSync(path.join(os.tmpdir(), 'statusline_data.json'), JSON.stringify(data, null, 2));
+  } catch (_) {}
+
   // --- Directory ---
   const cwd =
     (data.workspace && data.workspace.current_dir) ||
@@ -83,11 +89,36 @@ process.stdin.on('end', () => {
     `${DIM}` + ' '.repeat(BAR_WIDTH - filled) +
     `${barColor}] ${pct}%${R}`;
 
+  // --- 5h rate limit + cost ---
+  const fiveHour = data.rate_limits && data.rate_limits.five_hour;
+  const totalCost = data.cost && data.cost.total_cost_usd;
+
+  let usageSegment = null;
+  if (fiveHour || totalCost) {
+    const parts = [];
+    if (fiveHour) {
+      const fivePct = Math.round(fiveHour.used_percentage);
+      const fiveColor = fivePct >= 90 ? BAR_CRIT : fivePct >= 70 ? BAR_WARN : BAR_OK;
+      const fiveFilled = Math.round((fivePct / 100) * BAR_WIDTH);
+      const fiveBar =
+        `${fiveColor}[` +
+        '='.repeat(fiveFilled) +
+        `${DIM}` + ' '.repeat(BAR_WIDTH - fiveFilled) +
+        `${fiveColor}] ${fivePct}%${R}`;
+      parts.push(`5h ${fiveBar}`);
+    }
+    if (totalCost) {
+      parts.push(`${DIM}$${totalCost.toFixed(2)}${R}`);
+    }
+    usageSegment = parts.join(' ');
+  }
+
   // --- Assemble ---
   const segments = [`${CYAN}${displayDir}${R}`];
   if (gitBranch !== null) segments.push(`${GREEN}${gitBranch}${R}`);
   segments.push(`${MAGENTA}${model}${R}`);
   segments.push(bar);
+  if (usageSegment !== null) segments.push(usageSegment);
 
   process.stdout.write(segments.join(SEP) + '\n');
 });