feat: add bilingual labs and Node 24 workflows

[emmanuelknafo]

Added French workshop content alongside the existing English pages and updated GitHub Actions to Node 24-compatible runtimes.

Changes

Bilingual Workshop

• Added complete French home and seven lab pages while preserving English URLs and runnable examples.
• Added language-specific left navigation, same-page language switching, and page-level document language.
• Added a French homepage fallback for pages without a translated counterpart.
• Clarified the seven normal functional scenarios and two intentional failure demonstrations.

GitHub Workflows

• Updated checkout, setup-node, artifact, and Pages actions to Node 24-compatible versions.
• Set the test runtime to Node 24 and updated matching lab instructions.
• Preserved separate functional/accessibility jobs and report artifacts.

Validation

• Docker Jekyll build passed.
• All 16 paired pages passed language, navigation, counterpart-link, and workflow-expression checks.
• English and French responsive checks passed at 1440 and 375 pixels.
• Unpaired README fallback and paired lab switching returned valid destinations.
• Two parallel review groups completed; the broken counterpart-link finding was fixed.
• ADO Test Plan 3195, static Suite 3197, and Test Cases 3198-3200 were created with Tests links and Agentic AI tags.
• Hosted workflow runs confirmed no Node 20 action-runtime warnings.
• Post-merge Pages deployment and all 16 live pages were verified.

Related Issues

Fixes AB#3194

Notes

The existing functional suite includes two intentional failure demonstrations. Accessibility checks target the live Ontario.ca site and may report existing violations. This PR did not change those assertions. Local validation evidence was recorded on the ADO story, not as an executed ADO test run.

[emmanuelknafo]

Review complete: two parallel review groups found one broken counterpart link, fixed in 831852c and verified after a successful Jekyll build. CodeQL passed. Playwright run 34780597866: functional 8 passed/1 intentional title-mismatch failure; accessibility 1 passed/2 failures for live Ontario.ca violations. Assertions were unchanged. Full Playwright logs contained no Node 20 deprecation warnings. GitHub reported no required checks, required approvals, requested changes, or main branch rules. User authorized squash merge; no admin bypass will be used. CI is not being represented as green.