Add Docker distribution path for reproducible cross-platform toolkit use

[peetmate]

Title

Add Docker distribution path for reproducible cross-platform toolkit use

Summary

Brayden rated Docker worthwhile, especially for Windows pain points and
dependency/version drift. Current toolkit has many optional/runtime-heavy
dependencies plus Earth Engine auth expectations, so container support should be
designed deliberately rather than added as afterthought.

Why this matters

• easier onboarding on Windows
• reproducible runtime for demos and support
• cleaner base for CI, documentation, and future hosted workflows

Proposed work

1. Define target container use cases:
   • developer environment
   • CLI runtime for end users
   • CI helper image
2. Create initial Dockerfile with package install and console scripts.
3. Decide auth strategy for Earth Engine and Earthdata in container context.
4. Document volume mounts for:
   • outputs/cache
   • output files
   • optional station/custom input files
5. Add minimal smoke test for one CLI command inside container.

Acceptance criteria

• Dockerfile builds successfully
• at least one CLI smoke command works in container
• README documents intended Docker workflow and auth caveats

Notes

• lower priority than uv
• should not replace direct install path
• auth and cache persistence need explicit design

[peetmate]

Related pre-Docker staging issue: #80. Suggested sequence: stabilize direct-install workflow, env/auth docs, cache/output conventions, and smoke-tested entrypoints first; then wrap that stable surface with Docker.

[Sammyjoseph999]

Reopening: the Docker PR (#119) is still open and hasn't merged to main yet. This should auto-close when #119 merges.