fix: extract decorate-pr comment rendering from action yaml

decorate-pr/action.yml

@@ -328,37 +328,6 @@ runs:
           echo "$failure_reason" >&2
           exit 1
         fi
-    - name: Extract changelog unreleased entries
-      id: extract-changelog
-      shell: bash
-      env:
-        CHANGELOG: ${{ inputs.changelog }}
-      run: |
-        set -euo pipefail
-
-        if [[ ! -f "$CHANGELOG" ]]; then
-          printf 'unreleased_entries=%s\n' "" >> "$GITHUB_OUTPUT"
-          exit 0
-        fi
-
-        # Extract everything between [Unreleased] header and the next [X.Y.Z] header
-        unreleased="$(awk '
-          /^## \[Unreleased\]/ { in_unreleased=1; next }
-          /^## \[[0-9]+\.[0-9]+\.[0-9]+\]/ { if (in_unreleased) exit }
-          in_unreleased && NF { print }
-        ' "$CHANGELOG")"
-
-        # Use a temporary file to handle multiline content
-        tmp_file=$(mktemp)
-        printf '%s' "$unreleased" > "$tmp_file"
-        
-        # Read it back and set as output
-        delimiter="EOF_CHANGELOG"
-        printf '%s<<%s\n' "unreleased_entries<<$delimiter" "$delimiter" >> "$GITHUB_OUTPUT"
-        cat "$tmp_file" >> "$GITHUB_OUTPUT"
-        printf '%s\n' "$delimiter" >> "$GITHUB_OUTPUT"
-        
-        rm -f "$tmp_file"
 
     - name: Build PR comment markdown
       id: build-comment
@@ -373,102 +342,11 @@ runs:
         GATE_MODE: ${{ inputs.changelog-gate-mode }}
         DOCS_ONLY: ${{ steps.changelog-gate.outputs.docs_only }}
         ADDITIONS_COUNT: ${{ steps.changelog-gate.outputs.unreleased_additions_count }}
-        FAILURE_REASON: ${{ steps.changelog-gate.outputs.gate_failure_reason }}
+        FAILURE_REASON: ${{ steps.changelog-gate.outputs.failure_reason }}
       run: |
         set -euo pipefail
 
-        # Start building the comment
+        bash "$GITHUB_ACTION_PATH/build-comment.sh"
-        tmp_file=$(mktemp)
-        
-        # Add title and coverage section
-        cat > "$tmp_file" << 'EOF'
-<!-- vociferate-pr-review -->
-EOF
-        
-        printf '## %s\n\n' "$COMMENT_TITLE" >> "$tmp_file"
-        
-        # Coverage badge section
-        cat >> "$tmp_file" << EOF
-### Coverage
-![Coverage Badge]($BADGE_URL)
-
-**Coverage:** $COVERAGE_PCT%
-
-EOF
-        
-        # Changelog gate section (if enabled)
-        if [[ "$GATE_ENABLED" == "true" ]]; then
-          gate_status="✓ Pass"
-          if [[ "$GATE_PASSED" != "true" ]]; then
-            if [[ "$GATE_MODE" == "strict" ]]; then
-              gate_status="✗ Fail"
-            else
-              gate_status="⚠ Warning"
-            fi
-          fi
-
-          cat >> "$tmp_file" << EOF
-
-### Changelog Gate
-**Status:** $gate_status
-
-EOF
-          
-          if [[ "$DOCS_ONLY" == "true" ]]; then
-            cat >> "$tmp_file" << 'EOF'
-This PR only modifies documentation—changelog entry not required.
-
-EOF
-          elif [[ "$GATE_PASSED" == "true" ]]; then
-            cat >> "$tmp_file" << EOF
-Found $ADDITIONS_COUNT line(s) added to Unreleased section ✓
-
-EOF
-          else
-            cat >> "$tmp_file" << EOF
-**Issue:** $FAILURE_REASON
-
-**How to fix:** Add an entry under the appropriate subsection in the \`## [Unreleased]\` section of \`CHANGELOG.md\`. Use one of:
-- \`### Breaking\` for backwards-incompatible changes
-- \`### Added\` for new features
-- \`### Changed\` for behavior changes
-- \`### Removed\` for deprecated removals
-- \`### Fixed\` for bug fixes
-
-Example:
-\`\`\`markdown
-## [Unreleased]
-### Added
-- New changelog gate validation for PR decoration.
-\`\`\`
-
-EOF
-          fi
-        fi
-        
-        # Changelog section
-        if [[ -n "$UNRELEASED" ]]; then
-          cat >> "$tmp_file" << 'EOF'
-### Unreleased Changes
-
-EOF
-          printf '%s\n' "$UNRELEASED" >> "$tmp_file"
-          printf '\n' >> "$tmp_file"
-        fi
-        
-        # Add footer
-        cat >> "$tmp_file" << 'EOF'
----
-*This comment was automatically generated by [vociferate/decorate-pr](https://git.hrafn.xyz/aether/vociferate).*
-EOF
-        
-        # Store as output using delimiter
-        delimiter="EOF_COMMENT"
-        printf '%s<<%s\n' "comment_body<<$delimiter" "$delimiter" >> "$GITHUB_OUTPUT"
-        cat "$tmp_file" >> "$GITHUB_OUTPUT"
-        printf '%s\n' "$delimiter" >> "$GITHUB_OUTPUT"
-        
-        rm -f "$tmp_file"
 
     - name: Find and update/post PR comment
       id: post-comment

decorate-pr/build-comment.sh

@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+tmp_file=$(mktemp)
+trap 'rm -f "$tmp_file"' EXIT
+
+{
+  printf '%s\n' '<!-- vociferate-pr-review -->'
+  printf '\n## %s\n\n' "$COMMENT_TITLE"
+  printf '### Coverage\n'
+  printf '![Coverage Badge](%s)\n\n' "$BADGE_URL"
+  printf '**Coverage:** %s%%\n' "$COVERAGE_PCT"
+} > "$tmp_file"
+
+if [[ "$GATE_ENABLED" == "true" ]]; then
+  gate_status="Pass"
+  if [[ "$GATE_PASSED" != "true" ]]; then
+    if [[ "$GATE_MODE" == "strict" ]]; then
+      gate_status="Fail"
+    else
+      gate_status="Warning"
+    fi
+  fi
+
+  {
+    printf '\n### Changelog Gate\n'
+    printf '**Status:** %s\n\n' "$gate_status"
+  } >> "$tmp_file"
+
+  if [[ "$DOCS_ONLY" == "true" ]]; then
+    printf '%s\n\n' 'This PR only modifies documentation; changelog entry not required.' >> "$tmp_file"
+  elif [[ "$GATE_PASSED" == "true" ]]; then
+    printf 'Found %s line(s) added to Unreleased section.\n\n' "$ADDITIONS_COUNT" >> "$tmp_file"
+  else
+    printf '**Issue:** %s\n\n' "$FAILURE_REASON" >> "$tmp_file"
+    cat >> "$tmp_file" <<'EOF'
+**How to fix:** Add an entry under the appropriate subsection in the `## [Unreleased]` section of `CHANGELOG.md`. Use one of:
+- `### Breaking` for backwards-incompatible changes
+- `### Added` for new features
+- `### Changed` for behavior changes
+- `### Removed` for deprecated removals
+- `### Fixed` for bug fixes
+
+Example:
+```markdown
+## [Unreleased]
+### Added
+- New changelog gate validation for PR decoration.
+```
+
+EOF
+  fi
+fi
+
+if [[ -n "$UNRELEASED" ]]; then
+  {
+    printf '### Unreleased Changes\n\n'
+    printf '%s\n\n' "$UNRELEASED"
+  } >> "$tmp_file"
+fi
+
+cat >> "$tmp_file" <<'EOF'
+---
+*This comment was automatically generated by [vociferate/decorate-pr](https://git.hrafn.xyz/aether/vociferate).*
+EOF
+
+delimiter="EOF_COMMENT"
+printf 'comment_body<<%s\n' "$delimiter" >> "$GITHUB_OUTPUT"
+cat "$tmp_file" >> "$GITHUB_OUTPUT"
+printf '%s\n' "$delimiter" >> "$GITHUB_OUTPUT"