Harden GitHub Actions workflows

[hylarucoder]

Summary

• upgrade JavaScript actions to current major versions and use Node 24 for website builds
• make Docs use-case validation accept Learn more links and only warn for unlinked banner gaps
• add a website package presence check so the Pages workflow skips cleanly while benchmarks/EvoAgentBench/website is absent
• add EverCore Smoke, a lightweight PR/push workflow for methods/EverCore/** changes

EverCore Smoke coverage

The new workflow intentionally stays lightweight and avoids Docker, Milvus, Elasticsearch, Redis, and LLM dependencies. It currently checks:

• locked uv dependency installation
• whitespace via git diff --check
• Python compilation for API specs and the extraction demo
• stable DTO compatibility tests (tests/test_content_item_compat.py)
• a demo payload regression proving the new top-level content payload passes and the legacy text: {content} payload fails at messages.0.content

Why the website deploy target is missing

benchmarks/EvoAgentBench/website existed in earlier history, but it disappeared from the current mainline through merge 6c374f5. The deploy workflow was left behind and still pointed at that stale package path. This PR keeps the workflow safe by checking for package.json before build/deploy; if the website package is restored later, the Node 24 path is ready.

Verification

• ruby -e 'require "yaml"; Dir[".github/workflows/*.yml"].sort.each { |p| YAML.load_file(p); puts "YAML ok: #{p}" }'\n- local run of the Docs relative Markdown link check\n- local run of the Docs use-case banner/primary-link check\n- PYTHONPATH=src:. uv run pytest tests/test_content_item_compat.py -q\n- local run of the EverCore demo payload regression\n- PYTHONPATH=src:. uv run python -m compileall -q src/api_specs demo/extract_memory.py\n- git diff --check\n- GitHub checks: Docs / links SUCCESS, EverCore Smoke / smoke SUCCESS