docs: add launcher configuration reference

[floze-the-genius]

Summary

• add complete English and Chinese launcher configuration references
• document source-backed defaults, ports, MySQL/MongoDB behavior, and all container environment variables
• distinguish local Docker, source, and production-image configuration
• document all six host-side Compose port overrides separately from container/launcher ports
• add security guidance and link both references from the matching READMEs

Related issue

Closes #34

Type of change

Documentation

How has this been tested?

• exact rebase onto current master c52c08ad; original documentation patch preserved
• exact CI toolchain Go 1.25.12
• go mod verify
• gofmt check
• go vet -composites=false ./...
• Linux go build ./...
• all CI unit-test jobs plus the original targeted configuration tests
• docker compose config --quiet
• rendered Compose configuration with all six *_HOST_PORT overrides
• English/Chinese/source cross-check
• git diff --check

[floze-the-genius]

@yuwnloyblog I exact-rebased this onto current master (02fbb1e, 0 behind) and updated both English and Chinese references for the six host-side Compose port overrides added upstream, keeping host ports distinct from container/launcher ports. On Go 1.25.12, module verification, vet, Linux build, all CI unit-test jobs, Compose validation/rendering, EN/ZH/source cross-check, and diff check pass. The new CI run is stopped at action_required before jobs start. Could you approve the workflow and review when convenient?