feat(gha): Auto-publish releases

- GHA release workflow is updated to use an action for uploading all assets. The
	action docs say it updates a release if one already exists, and since this
	triggers on release and we pass a release tag we know the release already
	exists.
- GHA release candidate workflow is updated to auto-publish a pre-release
	release on push to a `release/**` branch. A script is added and used to
	generate a release message made up of the commits since the last release of
	any kind.
- ACT profiles are added to allow locally testing these workflows without
	needing to push and wait for GHA to run.
- Docs are updated to note how to test the workflows locally.

.github/workflows/release_candidate.yml

@@ -1,20 +1,25 @@
-name: Compile Release Candidate
+name: Publish Release Candidate
 
 on:
-  workflow_dispatch:
+  push:
+    branches:
+      - "release/**"
+
+permissions:
+  contents: write
 
 jobs:
   build-release-candidate:
-    if: startsWith(github.ref_name, 'release/')
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v6
         with:
           submodules: recursive
+          fetch-depth: 0
 
       - uses: actions/setup-python@v6
         with:
-          python-version: '3.14'
+          python-version: "3.14"
 
       - name: Install uv
         uses: astral-sh/setup-uv@v7
@@ -29,6 +34,8 @@ jobs:
         run: |
           echo "SHORT_SHA=${GITHUB_SHA::7}" >> $GITHUB_ENV
           echo "BRANCH_SUFFIX=${GITHUB_REF_NAME#release/}" >> $GITHUB_ENV
+          echo "RC_TAG=${GITHUB_REF_NAME#release/}-rc.${GITHUB_RUN_NUMBER}.${GITHUB_RUN_ATTEMPT}" >> $GITHUB_ENV
+          echo "RELEASE_NOTES_PATH=${RUNNER_TEMP}/release-notes.md" >> $GITHUB_ENV
 
       - name: Build CrossPoint Release Candidate
         env:
@@ -38,13 +45,30 @@ jobs:
       - name: Patch min_chip_rev_full to 0
         run: python3 scripts/patch_min_chip_rev.py .pio/build/gh_release_rc/firmware.bin
 
-      - name: Upload Artifacts
-        uses: actions/upload-artifact@v4
+      - name: Generate release notes
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: |
+          python3 scripts/generate_release_notes.py \
+            --output "${RELEASE_NOTES_PATH}" \
+            --target-sha "${GITHUB_SHA}" \
+            --current-label "${RC_TAG}" \
+            --release-scope any \
+            --exclude-tag "${RC_TAG}"
+
+      - name: Publish prerelease assets
+        if: ${{ env.ACT != 'true' }}
+        uses: softprops/action-gh-release@v2
         with:
-          name: CrossPoint-RC-${{ env.BRANCH_SUFFIX }}
-          path: |
+          tag_name: ${{ env.RC_TAG }}
+          target_commitish: ${{ github.sha }}
+          name: CrossPoint ${{ env.RC_TAG }}
+          body_path: ${{ env.RELEASE_NOTES_PATH }}
+          prerelease: true
+          files: |
             .pio/build/gh_release_rc/bootloader.bin
             .pio/build/gh_release_rc/firmware.bin
             .pio/build/gh_release_rc/firmware.elf
             .pio/build/gh_release_rc/firmware.map
             .pio/build/gh_release_rc/partitions.bin
+          fail_on_unmatched_files: true