[cmena92]

Closes #6

What is here

In the animals region of www/games/companero/index.html:

• All eight, the capybara first: capybara, fox, owl, cat, bear, rabbit, panda, otter. Animals not owned are drawn paler.
• Capybara: free for everyone.
• Rabbit 180, panda 260, otter 340: they show their price. With enough coins, the core's own confirmation (as in Capybara's shop) and, on accepting, a single charge; the animal is worn at once. Without enough coins, a toast with how many are missing and that playing earns them.
• The core's owl, cat and bear, if not owned, show «unlocked in your profile». They are never sold here: the companion does not write the core's unlocks (Crear economía e inventario seguros para el compañero #3).
• New strings in the five languages.

Nothing in the core changes; showing the new animals in the profile and menu stays out of scope (epic #2).

Checks run locally

• node tools/test-companero.js: 73 green. New, in a real browser: the rabbit's price, the owl locked with its note, the confirmation, the single charge (200 → 20), the rabbit worn, both persisting after a reload, the panda's toast with the 240 missing and no charge, the owl not buyable here with the core's unlocks untouched, and the capybara for free. The page source never calls coins.add or achievements.unlock.
• node tools/test.js: 5,482 green · ./tools/browser-check.sh: 50 of 50.
• Screenshots at 390 and 1280 px, with and without the rabbit, checked by the owner's agent.