Replace server startup with new config system

## Parent PRD

#1660

## What to build

Rewire `node-server.ts` to use the new config file loader from #1661 instead of `dotenv` and the old `EnvironmentValuesSchema`. TLS uses user-provided cert/key files only (no auto-generation). The server listens on `GE_PORT` (default 80), logs with pino using `GE_LOG_FORMAT` (`pretty` or `json`), and defaults to HTTP.

Delete the old `env.ts`, `server-config.ts` resolution logic, and `setup-ssl.sh`. The server should create an HTTP or HTTPS server based on `GE_TLS` with provided cert paths.

## Acceptance criteria

- [ ] `node-server.ts` uses the new config loader, no `dotenv` dependency
- [ ] Server starts on `GE_PORT` (default 80) over HTTP by default
- [ ] `GE_TLS=true` with `GE_TLS_CERT`/`GE_TLS_KEY` starts HTTPS server
- [ ] `GE_TLS=true` without cert/key files logs error and exits
- [ ] `GE_LOG_FORMAT=json` produces structured JSON logs, `pretty` produces human-readable logs
- [ ] Old `env.ts` and `server-config.ts` deleted or replaced
- [ ] `setup-ssl.sh` deleted
- [ ] Unit tests for TLS validation and server config resolution

## Blocked by

- Blocked by #1661

## User stories addressed

- User story 5
- User story 14

## Related Issues

- Part of #1660

Start with the new config file loader in #1661, then read node-server.ts and the existing env.ts and server-config.ts resolution logic. Check how setup-ssl.sh is used before removing it. Done means the server follows the listed GE_PORT, GE_TLS, certificate, and GE_LOG_FORMAT behaviors, with unit tests covering TLS validation and config resolution.

Written by the indexing model from the issue text.