feat(sidepanel): support configurable auto step delay

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

tests/auto-step-random-delay.test.js

@@ -0,0 +1,105 @@
+const assert = require('assert');
+const fs = require('fs');
+
+const source = fs.readFileSync('background.js', 'utf8');
+
+function extractFunction(name) {
+  const start = source.indexOf(`function ${name}(`);
+  if (start < 0) {
+    throw new Error(`missing function ${name}`);
+  }
+
+  const paramsStart = source.indexOf('(', start);
+  let paramsDepth = 0;
+  let paramsEnd = paramsStart;
+  for (; paramsEnd < source.length; paramsEnd += 1) {
+    const ch = source[paramsEnd];
+    if (ch === '(') paramsDepth += 1;
+    if (ch === ')') {
+      paramsDepth -= 1;
+      if (paramsDepth === 0) {
+        break;
+      }
+    }
+  }
+
+  const braceStart = source.indexOf('{', paramsEnd);
+  let depth = 0;
+  let end = braceStart;
+  for (; end < source.length; end++) {
+    const ch = source[end];
+    if (ch === '{') depth += 1;
+    if (ch === '}') {
+      depth -= 1;
+      if (depth === 0) {
+        end += 1;
+        break;
+      }
+    }
+  }
+
+  return source.slice(start, end);
+}
+
+const bundle = [
+  'const AUTO_STEP_RANDOM_DELAY_MIN_ALLOWED_SECONDS = 0;',
+  'const AUTO_STEP_RANDOM_DELAY_MAX_ALLOWED_SECONDS = 600;',
+  'const AUTO_STEP_RANDOM_DELAY_DEFAULT_MIN_SECONDS = 12;',
+  'const AUTO_STEP_RANDOM_DELAY_DEFAULT_MAX_SECONDS = 18;',
+  'const PERSISTED_SETTING_DEFAULTS = { autoStepRandomDelayMinSeconds: 12, autoStepRandomDelayMaxSeconds: 18 };',
+  extractFunction('normalizeAutoStepRandomDelaySeconds'),
+  extractFunction('normalizeAutoStepRandomDelayRange'),
+  extractFunction('getAutoStepRandomDelayMs'),
+].join('\n');
+
+const api = new Function(`${bundle}; return { normalizeAutoStepRandomDelaySeconds, normalizeAutoStepRandomDelayRange, getAutoStepRandomDelayMs };`)();
+
+const defaultRange = api.normalizeAutoStepRandomDelayRange({});
+assert.deepStrictEqual(defaultRange, { minSeconds: 12, maxSeconds: 18 }, 'missing settings should fall back to the default 12-18 second range');
+
+for (let i = 0; i < 200; i += 1) {
+  const delay = api.getAutoStepRandomDelayMs(defaultRange.minSeconds * 1000, defaultRange.maxSeconds * 1000);
+  assert.ok(delay >= 12000, `delay ${delay} should respect the lower bound`);
+  assert.ok(delay <= 18000, `delay ${delay} should respect the upper bound`);
+  assert.ok(Number.isInteger(delay), `delay ${delay} should be an integer`);
+}
+
+const samples = new Set(Array.from({ length: 50 }, () => api.getAutoStepRandomDelayMs(defaultRange.minSeconds * 1000, defaultRange.maxSeconds * 1000)));
+assert.ok(samples.size > 1, 'delay helper should produce randomized values');
+
+const customRange = api.normalizeAutoStepRandomDelayRange({
+  autoStepRandomDelayMinSeconds: 5,
+  autoStepRandomDelayMaxSeconds: 7,
+});
+assert.deepStrictEqual(customRange, { minSeconds: 5, maxSeconds: 7 }, 'configured ranges should be preserved when already valid');
+
+const collapsedRange = api.normalizeAutoStepRandomDelayRange({
+  autoStepRandomDelayMinSeconds: 20,
+  autoStepRandomDelayMaxSeconds: 10,
+});
+assert.deepStrictEqual(collapsedRange, { minSeconds: 20, maxSeconds: 20 }, 'max delay should collapse up to min delay when user input is inverted');
+
+assert.strictEqual(
+  api.getAutoStepRandomDelayMs(15000, 15000),
+  15000,
+  'equal bounds should produce a deterministic delay'
+);
+
+const originalRandom = Math.random;
+try {
+  Math.random = () => 0.6;
+  assert.strictEqual(
+    api.normalizeAutoStepRandomDelaySeconds(-50, 12),
+    0,
+    'negative configured delay should clamp to zero seconds'
+  );
+  assert.strictEqual(
+    api.getAutoStepRandomDelayMs(-50, 10),
+    6,
+    'lower bound should be clamped to zero and still allow random output'
+  );
+} finally {
+  Math.random = originalRandom;
+}
+
+console.log('auto step random delay tests passed');