feat: add human-like behavioral layer (humanize option)

Bezier mouse curves, per-character typing with mistype simulation,
smooth micro-step scrolling, idle micro-movements between actions.

Supports both sync and async Playwright APIs. Patches page, frame,
context, browser, and Locator class methods.

Two presets: 'default' (normal speed) and 'careful' (slower, deliberate).
Configurable via HumanConfig dataclass / interface with full override support.

Bug fixes (from PR review):
- fill()/clear(): platform-aware select-all (Meta+a on macOS, Control+a elsewhere)
- sync Locator check()/uncheck(): wrap mouse_move in RawMouse-compatible object
- resolve_config(): raise error on unknown preset name
- Lazy-load human.config via __getattr__ in __init__.py
- humanPreset typed as 'default' | 'careful' literal union
- browser.newPage() patches implicit context

Tests: Python 36/36, JS Vitest 34/34, visual Python 17/17, JS 13/13

js/src/human/keyboard.ts

@@ -0,0 +1,111 @@
+/**
+ * cloakbrowser-human — Human-like keyboard input.
+ */
+
+import type { Page } from 'playwright-core';
+import { RawKeyboard } from './mouse.js';
+import { HumanConfig, rand, randRange, sleep } from './config.js';
+
+const SHIFT_SYMBOLS = new Set([
+  '@', '#', '!', '$', '%', '^', '&', '*', '(', ')',
+  '_', '+', '{', '}', '|', ':', '"', '<', '>', '?', '~',
+]);
+
+const NEARBY_KEYS: Record<string, string> = {
+  a: 'sqwz', b: 'vghn', c: 'xdfv', d: 'sfecx', e: 'wrsdf',
+  f: 'dgrtcv', g: 'fhtyb', h: 'gjybn', i: 'ujko', j: 'hkunm',
+  k: 'jloi', l: 'kop', m: 'njk', n: 'bhjm', o: 'iklp',
+  p: 'ol', q: 'wa', r: 'edft', s: 'awedxz', t: 'rfgy',
+  u: 'yhji', v: 'cfgb', w: 'qase', x: 'zsdc', y: 'tghu',
+  z: 'asx',
+  '1': '2q', '2': '13qw', '3': '24we', '4': '35er', '5': '46rt',
+  '6': '57ty', '7': '68yu', '8': '79ui', '9': '80io', '0': '9p',
+};
+
+function getNearbyKey(ch: string): string {
+  const lower = ch.toLowerCase();
+  if (lower in NEARBY_KEYS) {
+    const neighbors = NEARBY_KEYS[lower];
+    const wrong = neighbors[Math.floor(Math.random() * neighbors.length)];
+    return ch === ch.toUpperCase() && ch !== ch.toLowerCase() ? wrong.toUpperCase() : wrong;
+  }
+  return ch;
+}
+
+export async function humanType(
+  page: Page,
+  raw: RawKeyboard,
+  text: string,
+  cfg: HumanConfig,
+): Promise<void> {
+  for (let i = 0; i < text.length; i++) {
+    const ch = text[i];
+
+    // Mistype chance — press wrong key, notice, backspace, then correct
+    if (Math.random() < cfg.mistype_chance && /[a-zA-Z0-9]/.test(ch)) {
+      const wrong = getNearbyKey(ch);
+      await typeNormalChar(raw, wrong, cfg);
+      await sleep(randRange(cfg.mistype_delay_notice));
+      await raw.down('Backspace');
+      await sleep(randRange(cfg.key_hold));
+      await raw.up('Backspace');
+      await sleep(randRange(cfg.mistype_delay_correct));
+    }
+
+    if (isUpperCase(ch)) {
+      await typeShiftedChar(raw, ch, cfg);
+    } else if (SHIFT_SYMBOLS.has(ch)) {
+      await typeShiftSymbol(page, raw, ch, cfg);
+    } else {
+      await typeNormalChar(raw, ch, cfg);
+    }
+
+    if (i < text.length - 1) {
+      await interCharDelay(cfg);
+    }
+  }
+}
+
+async function typeNormalChar(raw: RawKeyboard, ch: string, cfg: HumanConfig): Promise<void> {
+  await raw.down(ch);
+  await sleep(randRange(cfg.key_hold));
+  await raw.up(ch);
+}
+
+async function typeShiftedChar(raw: RawKeyboard, ch: string, cfg: HumanConfig): Promise<void> {
+  await raw.down('Shift');
+  await sleep(randRange(cfg.shift_down_delay));
+  await raw.down(ch);
+  await sleep(randRange(cfg.key_hold));
+  await raw.up(ch);
+  await sleep(randRange(cfg.shift_up_delay));
+  await raw.up('Shift');
+}
+
+async function typeShiftSymbol(page: Page, raw: RawKeyboard, ch: string, cfg: HumanConfig): Promise<void> {
+  await raw.down('Shift');
+  await sleep(randRange(cfg.shift_down_delay));
+  await raw.insertText(ch);
+  await page.evaluate((key: string) => {
+    const el = document.activeElement;
+    if (el) {
+      el.dispatchEvent(new KeyboardEvent('keydown', { key, bubbles: true }));
+      el.dispatchEvent(new KeyboardEvent('keyup', { key, bubbles: true }));
+    }
+  }, ch);
+  await sleep(randRange(cfg.shift_up_delay));
+  await raw.up('Shift');
+}
+
+function isUpperCase(ch: string): boolean {
+  return ch.length === 1 && ch >= 'A' && ch <= 'Z';
+}
+
+async function interCharDelay(cfg: HumanConfig): Promise<void> {
+  if (Math.random() < cfg.typing_pause_chance) {
+    await sleep(randRange(cfg.typing_pause_range));
+  } else {
+    const delay = cfg.typing_delay + (Math.random() - 0.5) * 2 * cfg.typing_delay_spread;
+    await sleep(Math.max(10, delay));
+  }
+}