Fix Beta article publication overflow

[jamiepratt]

Caution

AI-generated repair (OpenAI Codex). The repository owner explicitly authorized this focused repair for merge. The separate strict publication gate remains in #416 and still requires independent review.

Summary

• move the oversized Beta article CSS literals into byte-identical classpath resources
• move the shared explanation JavaScript literal into a byte-identical classpath resource
• leave CI policy, strict-gate scripts, and deployment behavior unchanged

Closes #414.

Model validation

Not applicable. No model, scorer, estimand, evidence, or promotion decision changed.

Software tests

• clj-paren-repair: both changed Clojure sources valid
• clojure -M:test-clj: 14 tests, 58 assertions, 0 failures/errors
• clojure -M:test-cljs: 10 tests, 45 assertions, 0 failures/errors
• affected Clay sources pass with JAVA_TOOL_OPTIONS=-Xss1m

Publication checks

• full Clay render under the server-sized 1 MiB stack: passed with no Clay FAILED: marker
• full Quarto render: 233/233 pages passed
• affected Beta page rendered successfully

Separation

The proposed strict renderer, historical rejection harness, pull-request workflow trigger, and deployment policy remain unmerged in #416 for review by other maintainers.