chore: import upstream snapshot with attribution

telemetry-worker/migrations/0016_web_subscription_analytics.sql

@@ -0,0 +1,40 @@
+-- Website analytics + token subscription plan events (migration 0016).
+--
+-- New event types:
+--   web_pageview, web_cta_click            (website beacon, anonymous visitor_id)
+--   subscription_login, subscription_activated,
+--   subscription_budget_exhausted, subscription_router_error
+--   account_linked                          (telemetry_id <-> account_id join anchor)
+--
+-- Column placement: production events sits at 96 of D1's 100-column hard cap
+-- (see the note in schema.sql and migrations/0013), so only the two columns
+-- every subscription dashboard query needs (account_id, tier) go on events
+-- (96 -> 98; scarce headroom remains, spend it carefully). The web-only
+-- fields live in a web_details detail table keyed by event_id, following the
+-- session_details / turn_details house pattern. Subscription events that
+-- carry a model reuse the existing generic events.model_start column (these
+-- are new event types, so no historical rows are re-interpreted).
+
+ALTER TABLE events ADD COLUMN account_id TEXT;
+ALTER TABLE events ADD COLUMN tier TEXT;
+
+CREATE TABLE IF NOT EXISTS web_details (
+    event_id TEXT PRIMARY KEY,
+    path TEXT,
+    referrer TEXT,
+    visitor_id TEXT,
+    utm_source TEXT,
+    utm_medium TEXT,
+    utm_campaign TEXT,
+    cta TEXT,
+    FOREIGN KEY (event_id) REFERENCES events(event_id)
+);
+
+-- Indexes for the README dashboard queries.
+-- Daily web visitors / pricing-page funnel group by visitor_id, path, cta:
+CREATE INDEX IF NOT EXISTS idx_web_details_visitor_id ON web_details(visitor_id);
+CREATE INDEX IF NOT EXISTS idx_web_details_path ON web_details(path);
+CREATE INDEX IF NOT EXISTS idx_web_details_cta ON web_details(cta);
+-- account_linked join + subscription rollups filter/group on these:
+CREATE INDEX IF NOT EXISTS idx_events_account_id ON events(account_id);
+CREATE INDEX IF NOT EXISTS idx_events_event_tier_created ON events(event, tier, created_at);