fix(tests): correct pg connection URL scheme and upgrade postgres service image

[Copilot]

All pg-based CI tests were timing out (64 failures). Two independent root causes:

1. Invalid connection URL scheme — test files used tcp:// instead of postgres://, which the pg library doesn't recognise, causing connection attempts to hang.
2. EOL postgres image — postgres:9.6-alpine (EOL Nov 2021) has TLS incompatibilities with Node.js 18/OpenSSL 3.x on the Ubuntu 24.04 Blacksmith runner, hanging all pg driver integration tests regardless of connection string.

Changes

• test/api.js, test/api.ts, test/postgresConnectionUrl.js — tcp:// → postgres:// in connection string constants
• .github/workflows/ci.yml — postgres service image 9.6-alpine → 16-alpine

[blacksmith-sh]

Found 64 test failures on Blacksmith runners:

Failures

Test	View Logs
API/"after all" hook for "Migrates down to 000"	View Logs
API/Emits migration events	View Logs
API/Emits validation events	View Logs
API/Implements getDatabaseVersion	View Logs
API/Migrates down to 000	View Logs
API/Migrates up to 003	View Logs
Driver: pg/"after all" hook for "Migrates down to 000 again"	View Logs
Driver: pg/"after all" hook for "Migrates down to 000"	View Logs
Driver: pg/Checksums generated SQL	View Logs
Driver: pg/Does not implement partial migrations	View Logs
Driver: pg/Errors on invalid md5 check	View Logs
Driver: pg/Handles current version	View Logs
Driver: pg/Handles failed migrations	View Logs
Driver: pg/Has migration details in schema table	View Logs
Driver: pg/Migrates down to 000	View Logs
Driver: pg/Migrates down to 000	View Logs
Driver: pg/Migrates down to 000 again	View Logs
Driver: pg/Migrates down to 000 again	View Logs
Driver: pg/Migrates down to 000 again	View Logs
Driver: pg/Migrates generated SQL	View Logs
Driver: pg/Migrates multiple versions up (000 -> 002)	View Logs
Driver: pg/Migrates one version up (002 -> 003	View Logs
Driver: pg/Migrates to "max"	View Logs
Driver: pg/Migrates to latest without input	View Logs
Driver: pg/Skips checksum validation if turned off	View Logs
Driver: pg (with currentSchema)/"after all" hook for "Migrates down to 000 again"	View Logs
Driver: pg (with currentSchema)/Checksums generated SQL	View Logs
Driver: pg (with currentSchema)/Errors on invalid md5 check	View Logs
Driver: pg (with currentSchema)/Handles current version	View Logs
Driver: pg (with currentSchema)/Has migration details in schema table	View Logs
Driver: pg (with currentSchema)/Migrates down to 000	View Logs
Driver: pg (with currentSchema)/Migrates down to 000 again	View Logs
Driver: pg (with currentSchema)/Migrates down to 000 again	View Logs
Driver: pg (with currentSchema)/Migrates down to 000 again	View Logs
Driver: pg (with currentSchema)/Migrates generated SQL	View Logs
Driver: pg (with currentSchema)/Migrates multiple versions up (000 -> 002)	View Logs
Driver: pg (with currentSchema)/Migrates one version up (002 -> 003	View Logs
Driver: pg (with currentSchema)/Migrates to "max"	View Logs
Driver: pg (with currentSchema)/Migrates to latest without input	View Logs
Driver: pg (with currentSchema)/Skips checksum validation if turned off	View Logs
Driver: pg (with schemaTable)/"after all" hook for "Migrates down to 000 again"	View Logs
Driver: pg (with schemaTable)/Checksums generated SQL	View Logs
Driver: pg (with schemaTable)/Errors on invalid md5 check	View Logs
Driver: pg (with schemaTable)/Handles current version	View Logs
Driver: pg (with schemaTable)/Has migration details in schema table	View Logs
Driver: pg (with schemaTable)/Migrates down to 000	View Logs
Driver: pg (with schemaTable)/Migrates down to 000 again	View Logs
Driver: pg (with schemaTable)/Migrates down to 000 again	View Logs
Driver: pg (with schemaTable)/Migrates down to 000 again	View Logs
Driver: pg (with schemaTable)/Migrates generated SQL	View Logs
Driver: pg (with schemaTable)/Migrates multiple versions up (000 -> 002)	View Logs
Driver: pg (with schemaTable)/Migrates one version up (002 -> 003	View Logs
Driver: pg (with schemaTable)/Migrates to "max"	View Logs
Driver: pg (with schemaTable)/Migrates to latest without input	View Logs
Driver: pg (with schemaTable)/Skips checksum validation if turned off	View Logs
Postgres connection url/"after all" hook for "Migrates down to 000"	View Logs
Postgres connection url/Migrates down to 000	View Logs
Postgres connection url/Migrates up to 003	View Logs
TypeScript:API/"after all" hook for "Migrates down to 000"	View Logs
TypeScript:API/Emits migration events	View Logs
TypeScript:API/Emits validation events	View Logs
TypeScript:API/Implements getDatabaseVersion	View Logs
TypeScript:API/Migrates down to 000	View Logs
TypeScript:API/Migrates up to 003	View Logs