fix(security): escape web search query output

[mstuart]

Summary

• escape untrusted web-search query text before rendering it in HTML
• cover script/image payloads, entity-like input, encoded input, and benign Unicode text
• preserve the current query parsing and public template API

Security impact

/search passed the raw HTTP request target value into both the <title> and <h1> HTML contexts. A raw request containing markup could therefore produce executable response HTML. The fix applies context-appropriate HTML text escaping at the shared rendering boundary.

Verification

• git diff --check
• cargo fmt --package code-memory -- --check
• cargo test web::templates::tests
• cargo test --test web_ui_test
• cargo clippy -- -D warnings
• cargo test
• manual raw-request reproduction: the original script payload is now emitted as <...>

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-24T23:13:39.238950Z	21ee683	PR opened
🔒 Security Review	✅ Completed 2026-09-24T23:14:47.348275Z	21ee683	PR opened

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