Clarify FY27 systems and networking hiring title

[fanyangCS]

Summary

Update only the hiring announcement title to Fan’s approved wording:

We’re Hiring: Systems & Networking Researchers (FY27)

• Only _news/we-are-hiring.md changes: one quoted YAML title value.
• Preserve /news/we-are-hiring/, date, full announcement copy, the System Intelligence SIGOPS hyperlink, and all three Microsoft application links.
• Based on production PR Link System Intelligence in hiring announcement #34 merge 0a13c425109d6e254317a4458428663dfb8a5b71.
• AI-generated implementation; wording approved by Fan.

Verification

• YAML parsed to the exact approved Unicode title (curly apostrophe, colon, ampersand, FY27).
• Reversing the title replacement reproduces the original file byte-for-byte.
• Prettier passed; repository tests passed (8 tests / 11 assertions); git diff --check passed.
• All CI and deployment checks passed: PR build, formatting, preview build/publish, and actual Pages deployment. Six successful jobs; one intentionally skipped preview-cleanup job; no failures, cancellations, or pending jobs.
• Verified publication provenance: source c99ce091765f22986e6fcf0e109c321194bb2163 → preview workflow push ba72bd6a07eac6bdfda421a044429c6220e511a8 → canonical-404-only child 73f60ef1272fd50d35ae2ab08b0ac22b14b7bfc7 → matching successful Pages deployment.
• Live HTTP 200 and parsed-HTML checks passed on preview homepage, news index, and announcement. Exact title/punctuation verified in homepage/index links, article H1, and browser title. All six paragraphs and four original hrefs are unchanged; slug remains /news/we-are-hiring/.
• Production homepage/index/detail were separately verified unchanged, still showing “We are hiring”. No browser visual-layout claim.
• Remote PR file/blob matches the tested local commit; working tree clean.

Preview / approval gate

• Homepage preview
• Announcement preview

Await Fan’s review of this new preview and explicit merge approval. This PR does not publish the title to production.