fix(gamification): plan-feature gating used wrong plan slugs (#285) (#304)

get_gamification_features() gated leaderboard / achievements / store off the
slugs 'professional' and 'basic', but the canonical platform_plans slugs are
free / starter / pro / business / enterprise. Every tenant on pro, starter, or
business fell through to the ELSE branch and had those features reported as
locked — so students at paying schools saw "Upgrade to Professional" on
features they already owned (e.g. the Point Store on a Pro school).

It also hardcoded the feature tiers instead of reading platform_plans.features,
the source get_plan_features() already uses. Rewrote it to resolve the plan the
same way and read leaderboard / achievements / store straight from
platform_plans.features, so the two functions can no longer drift.

Verified on Code Academy Pro (alice@student.com): store now renders all 6
items, balance + per-item pricing correct, insufficient-coins state correct,
and a successful redeem deducts coins and writes a gamification_redemptions row.

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: guillermoscript

docs/screenshots/gamification-store-285.gif

@@ -0,0 +1,49 @@
+-- Fix get_gamification_features: it gated gamification features off the wrong plan slugs.
+--
+-- The old CASE matched 'professional' / 'basic', but the canonical platform_plans
+-- slugs are free / starter / pro / business / enterprise. Every tenant on pro,
+-- starter, or business therefore fell through to the ELSE branch and had
+-- leaderboard / achievements / store wrongly reported as locked — so paying
+-- schools' students saw "Upgrade to Professional" on features they already own.
+--
+-- It also hardcoded the feature tiers instead of reading platform_plans.features,
+-- the authoritative source used by get_plan_features(). Fix: resolve the plan the
+-- same way get_plan_features() does and read store / leaderboard / achievements
+-- straight from platform_plans.features so the two functions can never drift.
+
+CREATE OR REPLACE FUNCTION public.get_gamification_features(_tenant_id uuid)
+ RETURNS jsonb
+ LANGUAGE plpgsql
+ STABLE SECURITY DEFINER
+AS $function$
+DECLARE
+  _plan_slug VARCHAR;
+  _features JSONB;
+BEGIN
+  -- Resolve the tenant's plan slug (same path as get_plan_features)
+  SELECT plan INTO _plan_slug FROM tenants WHERE id = _tenant_id;
+  _plan_slug := COALESCE(_plan_slug, 'free');
+
+  -- Pull the authoritative feature flags for that plan
+  SELECT pp.features INTO _features
+  FROM platform_plans pp
+  WHERE pp.slug = _plan_slug AND pp.is_active = true;
+
+  IF _features IS NULL THEN
+    SELECT pp.features INTO _features FROM platform_plans pp WHERE pp.slug = 'free';
+  END IF;
+
+  RETURN jsonb_build_object(
+    -- xp / levels / streaks ship on every plan, including free
+    'xp', true,
+    'levels', true,
+    'streaks', true,
+    'leaderboard', COALESCE((_features ->> 'leaderboard')::boolean, false),
+    'achievements', COALESCE((_features ->> 'achievements')::boolean, false),
+    'store', COALESCE((_features ->> 'store')::boolean, false),
+    -- custom gamification content unlocks at pro and above
+    'custom_achievements', _plan_slug IN ('pro', 'business', 'enterprise'),
+    'custom_store', _plan_slug IN ('pro', 'business', 'enterprise')
+  );
+END;
+$function$;