The March-era page had the right instincts (store state across swaps,
no manual DOM manipulation) but predated the @alpinejs/csp conversion
and never said the load-bearing fact: inline expressions are not
evaluated, so every x-data must reference an Alpine.data component —
which is why the whole attribute value is an expression and why
dynamic arguments go through JSONArg or data-attributes. Rewritten
with the banned list spelled out (inline handlers, hx-on*, js:
hx-vals, stray inline <script>) and each rule tied to the source that
enforces or embodies it (alpine.ts import, header.templ
whole-expression x-data, custom-section-builder data-attribute
pattern, bookPicker store as the living example). Every code sample
verified present in web/src.
John O'Keefe
35b210951a