feat: Add distillery enrichment cache

Caches AI enrichment results per distillery to save API calls:
- New table: enrichment_cache (distillery, tags, hit_count)
- New service: cache-enrichment.ts (get, save, increment, stats)
- enrich-data.ts checks cache before AI query
- Saves to cache after successful AI response
- Returns cached: true/false flag for transparency

Benefits:
- 0 API cost for repeated distillery scans
- Near-instant response for cached distilleries
- Shared across all users

enrichment_cache_migration.sql

@@ -0,0 +1,32 @@
+-- Enrichment Cache Table
+-- Caches AI enrichment results per distillery to save API calls
+
+CREATE TABLE IF NOT EXISTS enrichment_cache (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    distillery TEXT NOT NULL UNIQUE,
+    suggested_tags TEXT[],
+    suggested_custom_tags TEXT[],
+    search_string TEXT,
+    created_at TIMESTAMPTZ DEFAULT now(),
+    updated_at TIMESTAMPTZ DEFAULT now(),
+    hit_count INTEGER DEFAULT 0
+);
+
+-- Index for fast lookups
+CREATE INDEX IF NOT EXISTS idx_enrichment_cache_distillery 
+ON enrichment_cache(distillery);
+
+-- RLS: Allow all authenticated users to read (it's shared cache)
+ALTER TABLE enrichment_cache ENABLE ROW LEVEL SECURITY;
+
+DROP POLICY IF EXISTS "enrichment_cache_select" ON enrichment_cache;
+CREATE POLICY "enrichment_cache_select" ON enrichment_cache
+    FOR SELECT TO authenticated USING (true);
+
+DROP POLICY IF EXISTS "enrichment_cache_insert" ON enrichment_cache;
+CREATE POLICY "enrichment_cache_insert" ON enrichment_cache
+    FOR INSERT TO authenticated WITH CHECK (true);
+
+DROP POLICY IF EXISTS "enrichment_cache_update" ON enrichment_cache;
+CREATE POLICY "enrichment_cache_update" ON enrichment_cache
+    FOR UPDATE TO authenticated USING (true);