Prepare sample server.json exercising v2.0.0 extension fields

[LittleCoinCoin]

Context

This is a sub-issue of Issue #27 (draft v2.0.0 schema proposal). A concrete sample server.json serves two purposes:

1. Drives schema iteration during Issue Draft Hatch-Schemas v2.0.0 extension schema proposal #27 — authoring the sample makes schema gaps and awkward field names visible before the Day 1 meeting
2. Reused later: smoke-test hatch package validate and live registry round-trip both need a ready-made server.json to avoid blocking on authoring during hackathon sessions

Work on this alongside Issue #27, not after it.

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Task

Create examples/server_v2.0.0_example.json in the Hatch-Schemas repo (or in the hackathon working directory if the repo is not yet ready). The file must be a complete, valid server.json that exercises all v2.0.0 extension features.

Minimum required coverage

One entry per citations[] format type — at least one of each must appear:

"citations": [
  { "format": "doi",       "value": "10.1234/example",          "note": "primary paper" },
  { "format": "arxiv",     "value": "2301.12345",               "note": "preprint" },
  { "format": "pmid",      "value": "12345678",                 "note": "method reference" },
  { "format": "url",       "value": "https://example.org/docs", "note": "documentation" },
  { "format": "bibtex",    "value": "@article{key, ...}",       "note": "dataset" },
  { "format": "formatted", "value": "Author et al. (2024) ...", "note": "software" }
]

provenance{} both fields populated:

"provenance": {
  "git_sha": "abc1234",
  "build_env": "conda-lock"
}

schema_version set to the draft version:

"schema_version": "2.0.0"

All v1.2.2 dependencies types represented (at least one entry each):

"dependencies": {
  "python": [{ "name": "numpy", "version_constraint": "==1.26.0", "package_manager": "conda", "channel": "conda-forge" }],
  "system": [{ "name": "libgomp1", "version_constraint": "==12.3.0", "package_manager": "apt" }],
  "docker": [{ "name": "ghcr.io/example/image", "tag": "1.0.0", "digest": "sha256:abc123..." }],
  "hatch":  [{ "name": "io.github.example/peer-pkg", "version_constraint": "==0.1.0" }]
}

Also include a negative test case

Create a second file examples/server_v2.0.0_invalid_example.json that intentionally fails validation — for example, a citations entry with an unknown format value or a provenance block with neither field set.

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Acceptance Criteria

• examples/server_v2.0.0_example.json validates successfully against package/v2.0.0/hatch_pkg_metadata_schema.json
• All 9 citations[].format values are represented (or all values defined in the schema at the time of writing)
• provenance is populated with both git_sha and build_env
• All four dependencies types have at least one entry
• examples/server_v2.0.0_invalid_example.json fails validation with a clear, actionable error message
• Both files are committed on feat/schema-v2.0.0-extension

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References

• Parent issue: Draft Hatch-Schemas v2.0.0 extension schema proposal #27
• Alignment strategy: __reports__/crackingshells_alignment_strategy/01-alignment_strategy_v1.md § The Scientific Extension Contract