Tighten CI workflow assertions and use exit code for install detection

- Use grep -Fq with specific strings instead of broad pattern matches
- Use install command exit code instead of grepping for "Installation
  successful" to determine if chromium was installed
- Remove || true from quarto check install (no reason to suppress)
- Use set +e/set -e to capture exit codes without swallowing errors

Author: cderv

.github/workflows/test-install.yml

@@ -76,12 +76,15 @@ jobs:
         id: install-chromium
         shell: bash
         run: |
-          output=$(quarto install chromium --no-prompt 2>&1) || true
+          set +e
+          output=$(quarto install chromium --no-prompt 2>&1)
+          exit_code=$?
+          set -e
           echo "$output"
-          if echo "$output" | grep -q "deprecated"; then
+          if echo "$output" | grep -Fq "is deprecated"; then
             echo "deprecation-warning=true" >> "$GITHUB_OUTPUT"
           fi
-          if echo "$output" | grep -q "Installation successful"; then
+          if [ "$exit_code" -eq 0 ]; then
             echo "chromium-installed=true" >> "$GITHUB_OUTPUT"
           fi
 
@@ -96,9 +99,11 @@ jobs:
         id: update-chromium
         shell: bash
         run: |
-          output=$(quarto update chromium --no-prompt 2>&1) || true
+          set +e
+          output=$(quarto update chromium --no-prompt 2>&1)
+          set -e
           echo "$output"
-          if echo "$output" | grep -q "deprecated"; then
+          if echo "$output" | grep -Fq "is deprecated"; then
             echo "deprecation-warning=true" >> "$GITHUB_OUTPUT"
           fi
 
@@ -113,9 +118,9 @@ jobs:
         if: steps.install-chromium.outputs.chromium-installed == 'true'
         shell: bash
         run: |
-          output=$(quarto check install 2>&1) || true
+          output=$(quarto check install 2>&1)
           echo "$output"
-          if ! echo "$output" | grep -q "outdated"; then
+          if ! echo "$output" | grep -Fq "Chromium is outdated"; then
             echo "::error::Outdated Chromium warning missing from quarto check"
             exit 1
           fi