fix(release): use single stamp step for both push and dispatch triggers

.gitea/workflows/release.yaml

@@ -29,8 +29,8 @@ jobs:
     name: bump + tag
     runs-on: ubuntu-latest
     outputs:
-      version: ${{ steps.tag.outputs.tag_prefix }}
-      tag: ${{ steps.tag.outputs.tag_full }}
+      version: ${{ steps.stamp.outputs.version }}
+      tag: ${{ steps.stamp.outputs.tag }}
     steps:
       - uses: actions/checkout@v4
         with:
@@ -49,21 +49,21 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-cargo-prepare-
 
-      - name: Extract version from tag (push trigger)
-        if: github.event_name == 'push'
-        id: tag
-        run: |
-          echo "tag_prefix=${GITHUB_REF_NAME#v}" >> "$GITHUB_OUTPUT"
-          echo "tag=${GITHUB_REF_NAME}" >> "$GITHUB_OUTPUT"
-
-      - name: Validate version + stamp
-        if: github.event_name == 'workflow_dispatch'
+      - name: Stamp version + tag
         id: stamp
-        env:
-          VERSION: ${{ inputs.version }}
         run: |
           set -euo pipefail
-          ver="${VERSION#v}" # tolerate a leading v
+          if [ "${GITHUB_EVENT_NAME}" = "push" ]; then
+            # Tag push from local: tag already exists, just verify + extract version
+            tag="${GITHUB_REF_NAME}"
+            ver="${tag#v}"
+            if ! printf '%s' "$ver" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+([-.][0-9A-Za-z.-]+)?$'; then
+              echo "::error::'$ver' is not a semver version (expected e.g. 0.4.0)"
+              exit 1
+            fi
+          else
+            # Manual dispatch: validate input, stamp, verify tag doesn't exist yet
+            ver="${VERSION#v}"
             if ! printf '%s' "$ver" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+([-.][0-9A-Za-z.-]+)?$'; then
               echo "::error::'$ver' is not a semver version (expected e.g. 0.4.0)"
               exit 1
@@ -75,8 +75,11 @@ jobs:
               exit 1
             fi
             bash scripts/set-version.sh "$ver"
+          fi
           echo "version=$ver" >> "$GITHUB_OUTPUT"
           echo "tag=$tag" >> "$GITHUB_OUTPUT"
+        env:
+          VERSION: ${{ inputs.version }}
 
       # Gate: never tag code that doesn't build/test. If this fails nothing
       # is committed or pushed, so the release simply doesn't happen.