Update OG image: treehouse with person on deck (1200x630)

Add LINE share + native share (Web Share API) + deduplicate share logic

Mobile: auto-redirect ZH browsers + show language switcher on mobile

Security: replace email in referral URLs with non-reversible hash

Fix: email returning users now see referral link + share buttons instead of form

Update JSON-LD: friend referral messaging + offer URL → draw.html

i18n share text: detect browser language, ZH→中文 EN→English + friend referral messaging

Cats: they won't review your code, they just purr — and steal your bed

Fix referral tracking bugs + improve returning user UX

Add referrer input field: manual entry + auto-fill from ?ref= param

Major content refresh: friend referral as primary mechanic, UX improvements

Rebrand to 1+3 cat Treehouse across all pages and assets

Refine invitation copy: "招待你們住" + "大家跟你去" (tkman final)

Find three friends — viral referral loop messaging across all pages

Open giveaway to everyone: email = entry, GitHub & Claude Max = bonus tickets