decision/adr: record SemVer, template distribution, API versioning, container image, and cross-link strategy

[cdcavell]

Context

The v1.0.0 tag creates a SemVer commitment. The readiness assessment recommends recording several architectural decisions before the release so future changes are easier to classify and defend.

Acceptance Criteria

• ADR records the SemVer public surface for the template.
• ADR classifies which changes are MAJOR, MINOR, or PATCH for:
  • scaffolded project layout,
  • template parameters/symbols,
  • configuration key names/defaults,
  • default API route conventions,
  • default middleware ordering,
  • container image tag conventions,
  • internal class signatures.
• ADR records the template distribution model: NuGet-published dotnet new install vs clone-and-modify.
• ADR records the default API versioning scheme and rationale.
• ADR records the container base image strategy and tradeoffs.
• ADR records whether Zenodo/metadata should cross-link this repository to related SSRN works, and if so, what relationship type is appropriate.
• README and DocFX links point to these ADRs where release behavior depends on them.

Related

• Parent: v1.0.0 release readiness epic: final hardening and publication checklist #138
• Readiness Assessment: 4.4.1, 4.5.1, 4.8.1-4.8.5, Decisions D-1 through D-4