fix: add SELECT RLS policies to migration for community dashboard reads

All telemetry data is anonymous (no PII), so public reads via the
publishable key are safe. Needed for the community dashboard to
query skill popularity, crash clusters, and version distribution.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

supabase/migrations/001_telemetry.sql

@@ -43,17 +43,20 @@ CREATE TABLE update_checks (
   os TEXT NOT NULL
 );
 
--- RLS: anon key can INSERT only, never SELECT/UPDATE/DELETE
+-- RLS: anon key can INSERT and SELECT (all telemetry data is anonymous)
 ALTER TABLE telemetry_events ENABLE ROW LEVEL SECURITY;
 CREATE POLICY "anon_insert_only" ON telemetry_events FOR INSERT WITH CHECK (true);
+CREATE POLICY "anon_select" ON telemetry_events FOR SELECT USING (true);
 
 ALTER TABLE installations ENABLE ROW LEVEL SECURITY;
 CREATE POLICY "anon_insert_only" ON installations FOR INSERT WITH CHECK (true);
+CREATE POLICY "anon_select" ON installations FOR SELECT USING (true);
 -- Allow upsert (update last_seen)
 CREATE POLICY "anon_update_last_seen" ON installations FOR UPDATE USING (true) WITH CHECK (true);
 
 ALTER TABLE update_checks ENABLE ROW LEVEL SECURITY;
 CREATE POLICY "anon_insert_only" ON update_checks FOR INSERT WITH CHECK (true);
+CREATE POLICY "anon_select" ON update_checks FOR SELECT USING (true);
 
 -- Crash clustering view
 CREATE VIEW crash_clusters AS