✨ Add skills for EF migrations and new ADR creation

Introduces new skills for managing Entity Framework Core migrations
and creating Architectural Decision Records (ADRs). These skills
provide structured guidance for users to document architectural
decisions and manage database migrations effectively.

Co-authored-by: Copilot <copilot@github.com>

.github/skills/new-release/SKILL.md

@@ -0,0 +1,38 @@
+---
+name: new-release
+description: 'Cut a new release: tag the appropriate commit, generate the changelog, and produce build artifacts. Use when: releasing a new version, tagging a release, publishing NuGet packages, preparing release artifacts.'
+argument-hint: 'Branch or commit to release from (default: current main) and the kind of release (stable, prerelease, hotfix)'
+---
+
+# New Release
+
+Versioning is **GitVersion-driven** (`GitVersion.yml`). Do not hand-pick versions — let GitVersion compute them from branch and tag history.
+
+## Versioning
+
+| Branch | Label | Resulting version |
+| --- | --- | --- |
+| `main` | — | `MAJOR.MINOR.PATCH` (stable) |
+| `develop` / `dev` / `development` | `beta` | `MAJOR.MINOR.PATCH-beta.N` |
+| `release/*`, `hotfix/*`, `feature/*` | branch name | `…-<branch>.N` |
+
+- Tags use the prefix `v` (regex `[vV]?` also accepts `V` or none).
+- Only changes under `src/`, `Directory.Packages.props`, or `GitVersion.yml` increment the version.
+- Increments are suppressed for already-merged branches and already-tagged commits.
+
+## Procedure
+
+1. **Sync.** `git fetch --all --tags && git status` — confirm clean.
+2. **Compute.** `dotnet build -getProperty:Version` — verify the value matches expectations.
+3. **Pack.** `dotnet pack -c Release` (or use the [docker-build](../docker-build/SKILL.md) `pack` target). Artifacts land in `artifacts/nuget/`.
+4. **Tag.** `git tag -a v<version> -m "Release v<version>" && git push origin v<version>`.
+5. **Publish** packages to the configured feed.
+6. **Create the GitHub release** linked to the tag, using the generated changelog as notes.
+
+For hotfixes: branch from the latest stable tag (`git switch -c hotfix/<name> v<latest-stable>`), follow the procedure, then back-merge into `main` and `develop`.
+
+## Guardrails
+
+- **Tags are immutable** once pushed; never move or delete them.
+- **Never skip a `PATCH`** — ship a fix forward.
+- **Do not edit `GitVersion.yml` to force a version.** Address the underlying cause (missing tag, branch base, path filter, commit messages).