feature: add emoji width measurement to macOS CI builds

- Added pre-build measurement step for macOS runners
- Detects terminal type (Apple_Terminal or iTerm.app)
- Attempts to measure actual emoji widths using script command for pseudo-terminal
- Outputs measurements as artifacts for inspection and emoji-widths.json updates
- Uses continue-on-error to not block builds if measurement fails
- Measurements can be used to update plugin/emoji-widths.json with actual values

Author: cowwoc

.github/workflows/build-jlink-bundle.yml

@@ -69,6 +69,27 @@ jobs:
           java -version
           jlink --version
 
+      - name: Measure emoji widths (macOS only)
+        if: runner.os == 'macOS'
+        run: |
+          set -euo pipefail
+          TERMINAL=$(./plugin/scripts/measure-emoji-widths.sh --detect-only 2>/dev/null | grep "Terminal:" | sed 's/Terminal: //')
+          echo "Detected terminal: $TERMINAL"
+          echo "DETECTED_TERMINAL=$TERMINAL" >> $GITHUB_OUTPUT
+
+          # Attempt to measure widths using script command for pseudo-terminal
+          echo "Attempting to measure emoji widths..."
+          if script -q -e -c "./plugin/scripts/measure-emoji-widths.sh --json" /dev/null > emoji-widths-$TERMINAL.json 2>/dev/null; then
+            echo "✓ Measurements captured for $TERMINAL"
+            cat emoji-widths-$TERMINAL.json
+          else
+            echo "⚠ Could not measure widths (non-interactive terminal). Using hardcoded defaults for $TERMINAL."
+            # Store terminal detection result for reference
+            echo "{\"terminal\": \"$TERMINAL\", \"note\": \"measurement required interactive terminal, not available in CI\"}" > emoji-widths-$TERMINAL.json
+          fi
+        id: measure
+        continue-on-error: true
+
       - name: Build jlink bundle
         run: |
           set -euo pipefail
@@ -93,14 +114,21 @@ jobs:
           ls -lh "${BUNDLE_NAME}.tar.gz"
           sha256sum "${BUNDLE_NAME}.tar.gz" > "${BUNDLE_NAME}.tar.gz.sha256"
 
-      - name: Upload artifact
+      - name: Upload bundle artifact
         uses: actions/upload-artifact@v4
         with:
           name: cat-${{ steps.version.outputs.version }}-${{ matrix.platform }}
           path: |
             cat-${{ steps.version.outputs.version }}-${{ matrix.platform }}.tar.gz
             cat-${{ steps.version.outputs.version }}-${{ matrix.platform }}.tar.gz.sha256
 
+      - name: Upload emoji width measurements (macOS only)
+        if: runner.os == 'macOS' && hashFiles('emoji-widths-*.json') != ''
+        uses: actions/upload-artifact@v4
+        with:
+          name: emoji-measurements-${{ matrix.platform }}
+          path: emoji-widths-*.json
+
   release:
     needs: build
     runs-on: ubuntu-latest