feat: add Supabase schema, edge functions, and SQL views

Telemetry backend infrastructure: telemetry_events table with RLS
(insert-only), installations table for retention tracking,
update_checks for install pings. Edge functions for update-check
(version + ping), telemetry-ingest (batch insert), and
community-pulse (weekly active count). SQL views for crash
clustering and skill co-occurrence sequences.

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

supabase/migrations/001_telemetry.sql

@@ -0,0 +1,85 @@
+-- gstack telemetry schema
+-- Tables for tracking usage, installations, and update checks.
+
+-- Main telemetry events (skill runs, upgrades)
+CREATE TABLE telemetry_events (
+  id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
+  received_at TIMESTAMPTZ DEFAULT now(),
+  schema_version INTEGER NOT NULL DEFAULT 1,
+  event_type TEXT NOT NULL DEFAULT 'skill_run',
+  gstack_version TEXT NOT NULL,
+  os TEXT NOT NULL,
+  arch TEXT,
+  event_timestamp TIMESTAMPTZ NOT NULL,
+  skill TEXT,
+  session_id TEXT,
+  duration_s NUMERIC,
+  outcome TEXT NOT NULL,
+  error_class TEXT,
+  used_browse BOOLEAN DEFAULT false,
+  concurrent_sessions INTEGER DEFAULT 1,
+  installation_id TEXT  -- nullable, only for "community" tier
+);
+
+-- Index for skill_sequences view performance
+CREATE INDEX idx_telemetry_session_ts ON telemetry_events (session_id, event_timestamp);
+-- Index for crash clustering
+CREATE INDEX idx_telemetry_error ON telemetry_events (error_class, gstack_version) WHERE outcome = 'error';
+
+-- Retention tracking per installation
+CREATE TABLE installations (
+  installation_id TEXT PRIMARY KEY,
+  first_seen TIMESTAMPTZ DEFAULT now(),
+  last_seen TIMESTAMPTZ DEFAULT now(),
+  gstack_version TEXT,
+  os TEXT
+);
+
+-- Install pings from update checks
+CREATE TABLE update_checks (
+  id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
+  checked_at TIMESTAMPTZ DEFAULT now(),
+  gstack_version TEXT NOT NULL,
+  os TEXT NOT NULL
+);
+
+-- RLS: anon key can INSERT only, never SELECT/UPDATE/DELETE
+ALTER TABLE telemetry_events ENABLE ROW LEVEL SECURITY;
+CREATE POLICY "anon_insert_only" ON telemetry_events FOR INSERT WITH CHECK (true);
+
+ALTER TABLE installations ENABLE ROW LEVEL SECURITY;
+CREATE POLICY "anon_insert_only" ON installations FOR INSERT WITH CHECK (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);
+
+-- Crash clustering view
+CREATE VIEW crash_clusters AS
+SELECT
+  error_class,
+  gstack_version,
+  COUNT(*) as count,
+  COUNT(DISTINCT installation_id) as unique_users,
+  MIN(event_timestamp) as first_seen,
+  MAX(event_timestamp) as last_seen
+FROM telemetry_events
+WHERE outcome = 'error' AND error_class IS NOT NULL
+GROUP BY error_class, gstack_version
+ORDER BY count DESC;
+
+-- Skill sequence co-occurrence view
+CREATE VIEW skill_sequences AS
+SELECT
+  a.skill as skill_a,
+  b.skill as skill_b,
+  COUNT(DISTINCT a.session_id) as co_occurrences
+FROM telemetry_events a
+JOIN telemetry_events b ON a.session_id = b.session_id
+  AND a.skill != b.skill
+  AND a.event_timestamp < b.event_timestamp
+WHERE a.event_type = 'skill_run' AND b.event_type = 'skill_run'
+GROUP BY a.skill, b.skill
+HAVING COUNT(DISTINCT a.session_id) >= 10
+ORDER BY co_occurrences DESC;