18 data-driven achievements (achievements.json) across 8 trigger categories:
matches_played, matches_won, goals_scored, packs_opened, sbcs_completed,
cards_owned, level, objectives_completed, drafts_completed. Rarities span
common → epic. Coin rewards range from 500 (first_match) to 6000 (win_50).
check_and_unlock() queries the relevant metric from existing tables, skips
already-earned achievements via INSERT OR IGNORE, grants coin rewards, and
fires a persistent notification per unlock. Trigger values are cached per
call to avoid redundant DB round-trips for same-trigger achievements.
Checks run automatically after every match result (all triggers), every
pack open (packs_opened), and every successful SBC submission (sbcs_completed).
GET /achievements returns all definitions annotated with unlocked/unlocked_at,
plus earned and total counts. POST /matches/result response gains an
achievements_unlocked array (empty when nothing new unlocked).
AppState gains achievement_defs (Arc<Vec<AchievementDefinition>>) loaded
from data/achievements/**/*.json at startup — same pattern as obj_defs.
5 new tests: list endpoint, first_match unlock, first_win unlock, no-dup
guard, coin reward verification. Core now at 82 tests.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>