feat(web): switch to the Alpine CSP build; drop 'unsafe-eval' from CSP

Standard Alpine evaluates every attribute expression through
new Function(), which a strict Content-Security-Policy cannot allow.
Swap to the official CSP-safe build (@alpinejs/csp), whose parser
evaluates expressions against registered component scope without
eval. script-src now carries only 'self' and 'unsafe-inline' (the
latter still required by the pre-paint theme flash guard).

Bindings rewritten out of the unsupported expression shapes:
- 21 multi-statement sequences across admin, audio_reader, docs,
  header, index, and reader became single component methods
  (init/loadWatchStatus hooks, commitScrub, pickSkip, pickSpeed,
  pickDefaultSpeed, chooseSleepOption, chooseSleepClockMode,
  toggleFxInvert, openPageThumbs, submitNote, clearSearch,
  pickReadingTheme)
- the header sidebar's inline x-data (openPanel/themeMode IIFE)
  became a registered sidebarShell component; openPanel itself moved
  to the header root so every sidebar panel shares one open state
- the appearance-panel  moved into the component init()
- header init() now also seeds openPanel from localStorage (or the
  admin section on /admin pages)

Alpine magics (, , , ) remain available —
the CSP evaluator injects them into scope.

The Playwright suite covers the converted surfaces end to end.

web/src/reader/reader.ts

@@ -3587,6 +3587,27 @@ document.addEventListener("alpine:init", () => {
       this.readingMode = this.readingMode === "dark" ? "light" : "dark";
       this.applyTheme();
     },
+    // Popover/toolbar handlers (CSP-safe: single method calls from templ).
+    toggleFxInvert() {
+      this.fxInvert = !this.fxInvert;
+      this.applyFxFilter(true);
+    },
+    openPageThumbs() {
+      this.tocTab = "pages";
+      this.initPageThumbs();
+    },
+    submitNote() {
+      this.addNote(this.newNoteText);
+      this.newNoteText = "";
+    },
+    clearSearch() {
+      this.searchQuery = "";
+      this.clearSearchResults();
+    },
+    pickReadingTheme(value: string) {
+      this.readingTheme = value;
+      this.applyTheme();
+    },
     detectChromeDarkMode(): boolean {
       const darkChromeThemes = [
         "theme-tokyo-night",