Bring geoprocessor source and tests into cumulus-api

[oskarhurst]

The geoprocess worker currently downloads the processor package from USACE/cumulus-geoproc@main during its Docker build. Processor changes therefore require a separate repository push and can change an image without a corresponding Cumulus API commit.

This PR brings processor development and builds into this repository. Editing async_geoprocess/geoproc/src/cumulus_geoproc/processors/ and rebuilding geoprocess now uses that exact local source.

Changes

• Import the package, license, SNODAS resource, unit/integration tests, development runner, and documentation configuration from USACE/cumulus-geoproc at 0a25999. The first commit contains the unchanged upstream files; the second wires them into this repository. Historical commits remain in the source repository.
• Replace the remote Git ADD with a local package COPY. Remove the obsolete processor Git-ref build argument from Compose and image workflows.
• Let local Compose use the Dockerfile's GDAL 3.13.1 default, matching production and processor tests, instead of its old 3.9.1 override.
• Add a Docker test target, standalone test Compose service, VS Code devcontainer, and a PR workflow running the imported processor tests.
• Update local-development instructions. Keep the existing worker entrypoint, Python import name, and SQS message contract.

Reference grids remain in USACE/cumulus-geoproc-test-data, using the same 2025-11-04 release as the upstream test suite. Only the test image downloads that archive and installs development dependencies. Existing generated documentation stays in docs/async_geoprocess; the upstream generated test report is not imported.

Validation

• Production image: docker build -t cumulus-geoproc-migration-review async_geoprocess — passed.
• Test image: docker compose -f async_geoprocess/docker-compose.tests.yml build geoproc — passed.
• Full imported suite: docker compose -f async_geoprocess/docker-compose.tests.yml run --rm geoproc — 16 passed in 66 seconds, including reference-grid conversions and COG validation. Three warnings were emitted: one NumPy binary-size warning and two Python warnings about continue inside finally in imported processors.
• Production image smoke check: worker imports, all 66 processor plugins load, and the packaged SNODAS TIFF is present; default entrypoint and non-root user are retained.
• Main Compose, test Compose, and devcontainer Compose configuration validation — passed. VS Code itself was not launched.
• All 94 imported package/development-tool files match upstream byte for byte; 89 Python files parse successfully. Whitespace checks pass for the integration commit; existing whitespace in the unchanged import is preserved.

This validates processor execution with reference data, not a live SQS-to-API end-to-end run.

The original cumulus-geoproc repository is not archived or deleted by this PR. After merge, processor changes should be submitted here.