Ship the vsce toolchain as a Fallout plugin, and align the release pipeline with the framework

.config/dotnet-tools.json

@@ -2,8 +2,8 @@
   "version": 1,
   "isRoot": true,
   "tools": {
-    "fallout.globaltools": {
-      "version": "2026.1.0-preview.104.g6583d78d2c",
+    "fallout.globaltool": {
+      "version": "10.4.0",
       "commands": [
         "fallout"
       ]

.fallout/build.schema.json

@@ -24,12 +24,11 @@
     "ExecutableTarget": {
       "type": "string",
       "enum": [
-        "Compile",
-        "Pack",
-        "Publish",
-        "PublishMarketplace",
-        "PublishOpenVsx",
-        "Restore"
+        "CompileVsix",
+        "PackVsix",
+        "PublishVsix",
+        "RestoreVsix",
+        "VerifyVsixCredentials"
       ]
     },
     "Verbosity": {
@@ -108,7 +107,21 @@
     }
   },
   "allOf": [
-    {},
+    {
+      "properties": {
+        "PreRelease": {
+          "type": "boolean",
+          "description": "Mark the packaged extension as a marketplace pre-release"
+        },
+        "PublishVsixTo": {
+          "type": "array",
+          "description": "Publish only to these named registries (default: all configured VsixPublishTargets)",
+          "items": {
+            "type": "string"
+          }
+        }
+      }
+    },
     {
       "$ref": "#/definitions/FalloutBuild"
     }

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,10 @@
+<!-- Keep it terse: one-line summary, then short "what changed" bullets. -->
+<!-- Link the issue and summarize it — don't recite it. -->
+
+<!-- Apply ONE category label so this lands in the right release-notes section: -->
+<!--   breaking-change / enhancement / bug / security / dependencies / documentation -->
+<!-- Housekeeping with no user-facing note? Use skip-changelog instead. -->
+<!-- The taxonomy lives in .github/release.yml. -->
+
+<!-- The label IS the changelog — there is no CHANGELOG.md to update. -->
+<!-- Write the PR title as the line you'd want to read in the release notes. -->

.github/release.yml

@@ -0,0 +1,54 @@
+# Source of truth for the PR label taxonomy, mirroring the Fallout repo's own
+# .github/release.yml so contributors and tooling meet one convention across both.
+#
+# GitHub reads this to auto-generate release notes, grouping merged PRs into the
+# sections below by label. Releases are cut with `gh release create --generate-notes`,
+# so the label you put on a PR is what appears in the release.
+#
+# When raising a PR: apply the one category label that matches the change. A PR with
+# no category label falls through to "Other Changes" — prefer a real category.
+#
+# This is the ONLY changelog. There is no CHANGELOG.md — a hand-maintained file would
+# duplicate what these labels already record, and its version heading is unknowable in
+# advance anyway (the patch component is a Nerdbank.GitVersioning git height, so the
+# number is not settled until the release is cut). If the marketplace page ever needs
+# a rendered changelog, generate it into the .vsix at pack time from these notes.
+changelog:
+  exclude:
+    labels:
+      # skip-changelog: housekeeping with no consumer-facing note (CI, tooling,
+      # internal refactors). Keeps the notes signal-heavy.
+      - skip-changelog
+      # dependencies: dependency bumps — folded out of the notes as noise. Also a
+      # category below, so the label is documented once; the exclude wins.
+      - dependencies
+    authors:
+      - dependabot
+  categories:
+    # breaking-change: removes/renames a command ID, setting, or view ID; drops
+    # support for a VS Code or Fallout version; changes the build-graph contract.
+    - title: "⚠️ Breaking Changes"
+      labels:
+        - breaking-change
+    # enhancement: a new feature or user-facing capability.
+    - title: "✨ New Features"
+      labels:
+        - enhancement
+    # bug: fixes incorrect behavior.
+    - title: "🐛 Bug Fixes"
+      labels:
+        - bug
+    # security: fixes a vulnerability or hardens a security-sensitive surface.
+    - title: "🔒 Security"
+      labels:
+        - security
+    # dependencies: dependency version bumps (excluded above — kept for completeness).
+    - title: "📦 Dependencies"
+      labels:
+        - dependencies
+    # documentation: docs, comments, and agent-instruction changes only.
+    - title: "📖 Documentation"
+      labels:
+        - documentation
+    # Fallback for PRs carrying none of the labels above — don't rely on it.
+    - title: "Other Changes"

.github/workflows/build.yml

@@ -0,0 +1,56 @@
+# ------------------------------------------------------------------------------
+# <auto-generated>
+#
+#     This code was generated.
+#
+#     - To turn off auto-generation set:
+#
+#         [GitHubActions (AutoGenerate = false)]
+#
+#     - To trigger manual generation invoke:
+#
+#         fallout --generate-configuration GitHubActions_build --host GitHubActions
+#
+# </auto-generated>
+# ------------------------------------------------------------------------------
+
+name: build
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths-ignore:
+      - '**/*.md'
+      - '.github/**'
+      - '!.github/workflows/**'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ubuntu-latest:
+    name: ubuntu-latest
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+        with:
+          fetch-depth: 0
+          repository: ${{ github.event.pull_request.head.repo.full_name || github.repository }}
+          ref: ${{ github.head_ref }}
+      - name: 'Cache: .fallout/temp, ~/.nuget/packages'
+        uses: actions/cache@v6
+        with:
+          path: |
+            .fallout/temp
+            ~/.nuget/packages
+          key: ${{ runner.os }}-${{ hashFiles('**/global.json', '**/*.csproj', '**/Directory.Packages.props') }}
+      - name: 'Setup: .NET SDK'
+        uses: actions/setup-dotnet@v6
+        with:
+          global-json-file: global.json
+      - name: 'Restore: dotnet tools'
+        run: dotnet tool restore
+      - name: 'Run: PackVsix'
+        run: dotnet fallout PackVsix