c7cedb00d6
Everything about this feature had been exercised on SQLite only, which is the engine least likely to show its problems. Adds __tests__/integration/productUsagePg.test.js, following the gated pattern the .picpeak restore suites use: it runs the real migrations 201-203 against a real PostgreSQL and covers what SQLite cannot answer. node-postgres returns bigint as a STRING, and the withdrawal guard compares `cancel_seq` — a `'1' !== 1` slip there would let an activation complete after an opt-out, and SQLite, which hands back a number, would never show it. Booleans are real booleans rather than 0/1, which is what every `configured` signal in a report is built from. And markUsed takes SELECT ... FOR UPDATE on this engine only. Seven cases, all passing against PostgreSQL 15. Removing the compare-and-swap condition fails the withdrawal case there too, so the suite has teeth on that engine and not only on SQLite. CI already provides PICPEAK_PG_TEST_URL, so these run there rather than skipping. The collector default is harder to lose. An unset, empty or whitespace-only USAGE_COLLECTOR_URL now falls back to https://usage.picpeak.app — deployments that template the variable in (docker-compose writes ${USAGE_COLLECTOR_URL:-...}) can hand over an empty string, and that has to mean "use the default" rather than "no collector". A value that is present but malformed is still reported as a configuration error instead of being silently replaced: quietly retargeting a self-hoster's collector at ours would send their reports somewhere they did not choose. Refs #1110