Story 4.1: Task 1 Complete - PlayerPrivacyManager Core Logic

- Created src/contracts/privacy-settings.js with:
  - PrivacySettings typedef
  - PRIVACY_SETTINGS_DEFAULT (both flags false)
  - PRIVACY_SETTING_KEYS and FEATURE_NAME_MAP constants
  - createPrivacySettings() factory
  - isValidPrivacySettings() validator
  - validateSettingKey(), validateSettingValue(), validateFeatureName() helpers
- Created src/core/PlayerPrivacyManager.js with:
  - Constructor with FoundryAdapter DI validation
  - getSettings(userId) - retrieves settings from user flags
  - setSetting(userId, key, value) - async, validates, persists via user.setFlag
  - isOptedIn(userId, feature) - convenience method for feature checks
  - getAllSettings() - aggregates all users' settings (GM view)
  - onChange(callback) - subscription pattern for change events
  - teardown() - cleanup
- Created tests/unit/contracts/privacy-settings.test.js - 44 tests
- Created tests/unit/core/PlayerPrivacyManager.test.js - 35 tests
- All tests passing, lint clean
- Updated sprint-status.yaml: 4-1 from ready-for-dev to in-progress
- Updated story file: Task 1 subtasks 1.1-1.8 marked complete

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

src/contracts/privacy-settings.js

@@ -0,0 +1,151 @@
+/**
+ * Privacy Settings contract.
+ *
+ * Privacy settings control player opt-in/out for automation features that affect
+ * their on-screen presence. Settings are stored as user flags on the user document.
+ *
+ * Storage key: game.user.setFlag('video-view-manager', key, value)
+ * Shape: { reactionCamEnabled: boolean, hpReactiveCamStylingEnabled: boolean }
+ *
+ * @module contracts/privacy-settings
+ */
+
+/**
+ * @typedef {Object} PrivacySettings
+ * @property {boolean} reactionCamEnabled - Whether Reaction Cam automation is enabled for this user.
+ * @property {boolean} hpReactiveCamStylingEnabled - Whether HP-Reactive Cam Styling is enabled for this user.
+ */
+
+export const PRIVACY_SETTINGS_VERSION = 1;
+
+/**
+ * Default privacy settings - all features disabled by default (opt-in, not opt-out).
+ * @type {PrivacySettings}
+ */
+export const PRIVACY_SETTINGS_DEFAULT = {
+  reactionCamEnabled: false,
+  hpReactiveCamStylingEnabled: false,
+};
+
+/**
+ * Canonical list of privacy setting keys.
+ * @type {string[]}
+ */
+export const PRIVACY_SETTING_KEYS = Object.freeze([
+  "reactionCamEnabled",
+  "hpReactiveCamStylingEnabled",
+]);
+
+/**
+ * Feature name mapping for opt-in checks.
+ * @type {Object.<string, string>}
+ */
+export const FEATURE_NAME_MAP = Object.freeze({
+  reactionCam: "reactionCamEnabled",
+  hpReactiveCamStyling: "hpReactiveCamStylingEnabled",
+});
+
+/**
+ * Creates a new PrivacySettings object with defaults.
+ * Only known keys from PRIVACY_SETTINGS_DEFAULT are included; extra properties are ignored.
+ * @param {Partial<PrivacySettings>} [overrides={}] - Override default values.
+ * @returns {PrivacySettings}
+ */
+export function createPrivacySettings(overrides = {}) {
+  const result = { ...PRIVACY_SETTINGS_DEFAULT };
+  for (const key of PRIVACY_SETTING_KEYS) {
+    if (key in overrides) {
+      result[key] = overrides[key];
+    }
+  }
+  return result;
+}
+
+/**
+ * Validates a PrivacySettings DTO. Throws TypeError on any violation.
+ * @param {unknown} data - Value to validate.
+ * @returns {PrivacySettings} The validated settings.
+ * @throws {TypeError} If data fails validation.
+ */
+export function isValidPrivacySettings(data) {
+  if (data === null) {
+    throw new TypeError("PrivacySettings: must be an object");
+  }
+  if (typeof data !== "object" || Array.isArray(data)) {
+    throw new TypeError("PrivacySettings: must be an object");
+  }
+  const obj = /** @type {Record<string, unknown>} */ (data);
+  const { reactionCamEnabled, hpReactiveCamStylingEnabled, ...rest } = obj;
+  if (Object.keys(rest).length > 0) {
+    throw new TypeError(
+      `PrivacySettings: unknown keys: ${Object.keys(rest).join(", ")}`
+    );
+  }
+  if (typeof reactionCamEnabled !== "boolean") {
+    throw new TypeError(
+      `PrivacySettings: reactionCamEnabled must be a boolean, got ${typeof reactionCamEnabled}`
+    );
+  }
+  if (typeof hpReactiveCamStylingEnabled !== "boolean") {
+    throw new TypeError(
+      `PrivacySettings: hpReactiveCamStylingEnabled must be a boolean, got ${typeof hpReactiveCamStylingEnabled}`
+    );
+  }
+  return /** @type {PrivacySettings} */ (data);
+}
+
+/**
+ * Validates a single privacy setting key.
+ * @param {string} key - The setting key to validate.
+ * @returns {string} The validated key.
+ * @throws {TypeError} If key is invalid.
+ */
+export function validateSettingKey(key) {
+  if (typeof key !== "string" || key.length === 0) {
+    throw new TypeError("Setting key must be a non-empty string");
+  }
+  if (!PRIVACY_SETTING_KEYS.includes(key)) {
+    throw new TypeError(
+      `PrivacySettings: unknown key '${key}'. Valid keys: ${PRIVACY_SETTING_KEYS.join(
+        ", "
+      )}`
+    );
+  }
+  return key;
+}
+
+/**
+ * Validates a single privacy setting value.
+ * @param {unknown} value - The value to validate.
+ * @returns {boolean} The validated value.
+ * @throws {TypeError} If value is invalid.
+ */
+export function validateSettingValue(value) {
+  if (typeof value !== "boolean") {
+    throw new TypeError(
+      `PrivacySettings: value must be a boolean, got ${typeof value}`
+    );
+  }
+  return value;
+}
+
+/**
+ * Validates a feature name for opt-in checks.
+ * @param {string} feature - The feature name to validate.
+ * @returns {string} The validated feature name.
+ * @throws {TypeError} If feature is invalid.
+ */
+export function validateFeatureName(feature) {
+  if (typeof feature !== "string" || feature.length === 0) {
+    throw new TypeError("Feature name must be a non-empty string");
+  }
+  const validFeatures = Object.keys(FEATURE_NAME_MAP);
+  if (!validFeatures.includes(feature)) {
+    throw new TypeError(
+      `PrivacySettings: unknown feature '${feature}'. Valid features: ${validFeatures.join(
+        ", "
+      )}`
+    );
+  }
+  return feature;
+}