Update release processes to support release servicing branches (#1620)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jeffhandley

.github/workflows/release.md .github/release-process.md.github/workflows/release.md renamed to .github/release-process.md

@@ -10,7 +10,7 @@ The following process is used when publishing new releases to NuGet.org.
 
 ## 2. Prepare the release
 
-From a local clone of the repository, use Copilot CLI to invoke the `prepare-release` skill. The skill assesses the semantic version, bumps the version in [`src/Directory.Build.props`](../../src/Directory.Build.props), runs API compatibility checks, reviews documentation, drafts release notes, and creates a pull request with all release artifacts.
+From a local clone of the repository, use Copilot CLI to invoke the `prepare-release` skill. The skill assesses the semantic version, bumps the version in [`src/Directory.Build.props`](../src/Directory.Build.props), runs API compatibility checks, reviews documentation, drafts release notes, and creates a pull request with all release artifacts.
 
 Review the PR, request changes if needed, and merge when ready.
 
@@ -20,6 +20,15 @@ After the prepare-release PR is merged, invoke the `publish-release` skill. The
 
 Review the draft release on GitHub, check 'Set as a pre-release' if appropriate, and click 'Publish release'.
 
+## Branching
+
+The `main` branch is the next-MAJOR preview and development line; currently, it produces the `2.0.0-preview.*` series. Nightly `cron` CI on `main` publishes CI-suffixed packages to GitHub Packages.
+Long-lived `release/{MAJOR}.x` branches are created on demand when a shipped MAJOR needs servicing releases. Every push to a `release/*` branch publishes a CI-suffixed package to GitHub Packages, so servicing CI packages are commit-driven rather than clock-driven.
+Short-lived `release-{version}` branches are local prepare-release work branches that become pull requests, such as `release-2.0.0-preview.1` or `release-1.3.1`.
+Official NuGet.org publishes occur only when a GitHub Release is created from a branch's tag.
+The prepare-release skill asks for the source/base branch first so the release PR targets the same line it assessed.
+For the agent-facing, structured version of these rules, see [release-branches.md](skills/shared-resources/release-branches.md).
+
 ## 4. Monitor the Release workflow
 
 - After publishing, a workflow will produce build artifacts and publish the NuGet packages to NuGet.org

.github/skills/bump-version/SKILL.md

@@ -8,18 +8,21 @@ compatibility: Requires gh CLI with repo access for creating branches and pull r
 
 Assess and bump the SDK version in `src/Directory.Build.props` to prepare for the next release. This skill owns the [Semantic Versioning 2.0.0](https://semver.org/spec/v2.0.0.html) assessment logic — the [SemVer assessment guide](references/semver-assessment.md) is the single source of truth for version assessment criteria used across the release workflow by both the **prepare-release** and **publish-release** skills.
 
+Use the shared [release branch reference](../shared-resources/release-branches.md) for branch roles, previous-release lookup rules, and release work-branch naming.
+
 > **Note**: For comprehensive release preparation — including ApiCompat/ApiDiff, documentation review, and release notes — use the **prepare-release** skill, which incorporates version assessment as part of its broader workflow.
 
 ## Process
 
 ### Step 1: Read Current Version and Previous Release
 
-Read `src/Directory.Build.props` on the default branch and extract:
+Read `src/Directory.Build.props` on the current branch and extract:
 - `<VersionPrefix>` — the `MAJOR.MINOR.PATCH` version
+- `<VersionSuffix>` — the prerelease suffix, when present
 
-Display the current version to the user.
+The candidate version is `{VersionPrefix}` plus `-{VersionSuffix}` when the suffix is present (for example, `2.0.0-preview.1`). Display the current candidate version to the user.
 
-Determine the previous release tag from `gh release list` (most recent **published** release). Draft releases must be ignored — they represent a pending release that has not yet shipped. Use `--exclude-drafts` or filter to only published releases when querying.
+Determine the previous release tag from `gh release list` (most recent **published** release). Draft releases must be ignored — they represent a pending release that has not yet shipped. Use `--exclude-drafts` or filter to only published releases when querying. The lookup is branch-aware: from a `release/{MAJOR}.x` branch, restrict candidates to tags matching `v{MAJOR}.*`; from `main`, use the most recent published release globally. See [release-branches.md](../shared-resources/release-branches.md) for details.
 
 ### Step 2: Assess and Determine Next Version
 
@@ -40,26 +43,31 @@ When context about queued changes is available or can be gathered, assess the ve
 
 #### Default Suggestion (Fallback)
 
-When a quick bump is needed without full change analysis, suggest the next **minor** version:
+When a quick bump is needed without full change analysis, suggest based on the candidate version:
 
-- Current `1.0.0` → suggest `1.1.0`
-- Current `1.2.3` → suggest `1.3.0`
+- **Stable candidate** — suggest the next **minor** version:
+  - Current `1.0.0` → suggest `1.1.0`
+  - Current `1.2.3` → suggest `1.3.0`
+- **Prerelease candidate** — if the suffix starts with an identifier such as `preview.` or `rc.` followed by an integer, suggest incrementing the trailing integer:
+  - Current `2.0.0-preview.1` → suggest `2.0.0-preview.2`
+  - Current `2.0.0-rc.1` → suggest `2.0.0-rc.2`
 
 Present the suggestion and let the user confirm or provide an alternative.
 
-Parse the confirmed version into its `VersionPrefix` component.
+Parse the confirmed version into its `VersionPrefix` and `VersionSuffix` components. Stable versions have no suffix.
 
 ### Step 3: Create Pull Request
 
-1. Create a new branch named `bump-version-to-{version}` (e.g. `bump-version-to-1.1.0`) from the default branch
+1. Create a new branch named `bump-version-to-{version}` (e.g. `bump-version-to-1.1.0`) from the current branch
 2. Update `src/Directory.Build.props`:
-   - Set `<VersionPrefix>` to the new version
+   - Set `<VersionPrefix>` to the confirmed stable component
+   - Set `<VersionSuffix>` for prerelease versions, or clear it for stable versions; add the element if it is missing
    - Update `<PackageValidationBaselineVersion>` if the MAJOR version has changed
 3. Commit with message: `Bump version to {version}`
 4. Push the branch and create a pull request:
    - **Title**: `Bump version to {version}`
    - **Label**: `infrastructure`
-   - **Base**: default branch
+   - **Base**: the current branch (which, for a servicing branch like `release/1.x`, is that servicing branch — not `main`)
 
 ### Step 4: Confirm
 

.github/skills/bump-version/references/semver-assessment.md

@@ -56,13 +56,31 @@ Recommend a PATCH version increment if no MAJOR or MINOR criteria are met.
    - MINOR: `MAJOR.(MINOR+1).0`
    - PATCH: `MAJOR.MINOR.(PATCH+1)`
 
-**Examples** from previous release `v1.2.0`:
+### Prereleases
 
-| Level | Recommended |
-|-------|-------------|
-| PATCH | `v1.2.1` |
-| MINOR | `v1.3.0` |
-| MAJOR | `v2.0.0` |
+While the candidate version uses a prerelease suffix (e.g., `X.Y.Z-preview.N`, `X.Y.Z-rc.N`), the recommended next version increments the trailing integer of the suffix: `preview.3` → `preview.4`, `rc.1` → `rc.2`.
+
+Going to GA drops the suffix entirely: `2.0.0-rc.2` → `2.0.0`.
+
+This is purely about how to *compute* the next version. It does **not** declare any new policy about what kinds of changes are permitted between previews — refer to the existing [versioning documentation](../../../../docs/versioning.html) for breaking-change policy.
+
+### Branch context
+
+The "previous release" lookup is constrained to tags matching `v{MAJOR}.*` when assessing from a `release/{MAJOR}.x` servicing branch. On `main`, the lookup is unconstrained (most recent published release globally).
+
+The MAJOR/MINOR/PATCH classification criteria above are unchanged regardless of branch.
+
+See [release-branches.md](../../shared-resources/release-branches.md) for branch-role definitions and previous-release lookup rules.
+
+**Examples**:
+
+| Previous release   | Branch        | Level                 | Recommended            |
+|--------------------|---------------|-----------------------|------------------------|
+| `v1.2.0`           | `main`        | PATCH                 | `v1.2.1`               |
+| `v1.2.0`           | `main`        | MINOR                 | `v1.3.0`               |
+| `v1.2.0`           | `main`        | MAJOR                 | `v2.0.0`               |
+| `v2.0.0-preview.1` | `main`        | (prerelease bump)     | `v2.0.0-preview.2`     |
+| `v1.3.0`           | `release/1.x` | PATCH                 | `v1.3.1`               |
 
 ## Comparing Against the Candidate Version
 
@@ -83,6 +101,7 @@ Present the assessment as a summary table followed by a rationale:
 
 | Aspect | Finding |
 |--------|---------|
+| Branch context | release/1.x |
 | Previous release | v1.0.0 |
 | Breaking changes | None confirmed |
 | New API surface | Yes — 3 PRs add new public APIs |