feat: add landing-style start screen with four start modes

Phase 3 of turning the game into the company landing page.

- Replace the Iran-map briefing with a brand start screen over the
  orbiting 3D factory: logo, tagline and four ways in.
- Real world: safety notice, then GPS; if location is denied or
  missing, a friendly dialog offers offline play instead.
- Offline: start at Park Mellat beside the family car with the route
  to the factory, where the first purchase mission is.
- About Us: start in the factory yard. Products: start at the machine
  samples with the showroom open.
- Contact, address with map links, FAQ, careers, gallery and social
  links open in a sheet (bottom sheet on phones) from company config.
- Restart replays the chosen mode. Layout scrolls on short screens and
  respects safe areas.
- Add tests for the start screen, map links and theme.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/game/runtime/runtimeLifecycle.js

@@ -3,7 +3,6 @@ import { createState } from '../economy/gameState.js';
 import { createPayment } from '../economy/payment.js';
 import { createVendingMachine } from '../models/vending.js';
 import { resetGarage } from './garage.js';
-import { strings } from '../../i18n/fa.js';
 import { COMPANY } from '../../config/company.js';
 
 // Brand colours for materials and canvas drawings.
@@ -121,26 +120,3 @@ export function reset(context) {
   context.keys.clear();
   context.refreshHUD();
 }
-
-// ---------- Input ----------
-/**
- * Runs the start mission operation for this subsystem.
- * @param {*} context - context.
- * @returns {*} Operation result, when applicable.
- */
-export function startMission(context) {
-  context.ui.patch('briefing', {
-    hidden: true,
-  });
-  context.ui.patch('hud', {
-    hidden: false,
-  });
-  const { dialogue } = strings;
-  context.say('robot', dialogue.showroomIntro, 'wink');
-  context.say('child', dialogue.childAsksFactory);
-  context.say('father', dialogue.fatherAnswersFactory);
-  context.say('child', dialogue.childAsksArrival);
-  context.say('father', dialogue.fatherAnswersArrival);
-  if (!context.isTouch && !context.real.on)
-    context.canvas.requestPointerLock?.()?.catch?.(() => {});
-}