fix(ps-cache-kotlin): correct README ports, DB config, and reproduction steps

[slayerjain]

Summary

• Fix app port: 8080 (not 8090) per application.properties
• Fix DB config: testdb/postgres/postgres on port 5432 (not demodb/testpass on 5433)
• Add Docker Compose as the recommended setup approach
• Document environment variables with their defaults
• Fix scoring description: +5 tiebreaker bonus (not +50/-50)
• Add note about variable test numbering depending on health-check captures
• Quote curl URLs for shell safety

What was wrong

The README had port 8090 and database demodb:5433 with password testpass, but the actual application.properties defaults to port 8080 and testdb:5432 with password postgres. Following the README as-is would result in connection failures.

Test plan

• Follow Option B (standalone) from the updated README on a fresh machine
• Verify docker compose up --build works with Option A
• Verify all curl commands connect successfully on port 8080

[Copilot]

Pull request overview

Updates the ps-cache-kotlin reproduction README to match the app’s real defaults (ports/DB), provide a Docker Compose path, and clarify the expected failure behavior when replaying captured traffic.

Changes:

• Corrects documented HTTP port and Postgres connection defaults to align with application.properties.
• Adds a Docker Compose–based setup path and documents env vars/defaults.
• Clarifies reproduction steps/output (quoting curl URLs, updating failure description and scoring narrative).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

In Option A, docker-compose.yml publishes Postgres on host port 5433 ("5433:5432"), but the README never states this. If a user tries to connect from the host using the documented default DB_PORT=5432, they’ll hit the wrong port. Consider either changing the compose port mapping to 5432:5432 or explicitly noting the host-exposed port for Compose setups.

Suggested change

	This starts PostgreSQL (with schema + seed data via `init.sql`) and the app on port 8080.
	This starts PostgreSQL (with schema + seed data via `init.sql`) and the app on port 8080. For host access in the Docker Compose setup, PostgreSQL is exposed on `localhost:5433` (container port `5432`).

[Copilot]

spring.sql.init.mode=never disables Spring’s SQL initialization, but the table currently says the schema is created externally “(via init.sql)”. That’s only true for the Docker Compose path; the standalone steps create the schema via psql heredoc. Consider rewording to something like “Schema created outside Spring Boot (e.g., Postgres init.sql or manual psql)" to avoid implying Spring uses init.sql.

Suggested change

	| `spring.sql.init.mode` | `never` | Schema created externally (via init.sql) |
	| `spring.sql.init.mode` | `never` | Schema created outside Spring Boot (e.g., Postgres `init.sql` or manual `psql`) |