fix(web): complete the CSP-build migration across remaining surfaces

- audio reader: scrub/volume/speed/genre-tick bindings converted to
  component methods (onScrubInput, setVolumeFromEvent,
  applyDefaultSpeedFromSelect, volumeLabel, railTickStyle,
  isSkipActive/isSpeedActive) — these used Number/Math/String globals
  that the CSP evaluator cannot resolve
- fmtTime restored to the audioReader component: the unexport pass
  had ripped it from the Alpine.data object (time displays were dead)
- book detail: cover-upload click and banner edit validation moved to
  component methods (triggerCoverUpload, bannerEditHasText)
- admin/docs/index components: init() hooks for their x-init chains
- CSP header: 'unsafe-eval' dropped — the CSP build needs no eval
- e2e spec: replace test.info().annotate (unavailable in this
  Playwright version) with console logging

internal/middleware/security_headers.go

@@ -13,7 +13,11 @@ func SecurityHeadersMiddleware() echo.MiddlewareFunc {
 			c.Response().Header().Set("X-Frame-Options", "DENY")
 			c.Response().Header().Set("X-XSS-Protection", "1; mode=block")
 			c.Response().Header().Set("Strict-Transport-Security", "max-age=31536000; includeSubDomains; preload")
-			c.Response().Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:")
+			// script-src notes: 'unsafe-inline' is required by the pre-paint
+			// theme flash guard (inline <script>). Alpine runs via its
+			// CSP-safe build (@alpinejs/csp), which needs no eval — do NOT
+			// add 'unsafe-eval' here without removing that build.
+			c.Response().Header().Set("Content-Security-Policy", "default-src 'self'; script-src 'self' 'unsafe-inline'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https:; font-src 'self' data:")
 			c.Response().Header().Set("Referrer-Policy", "strict-origin-when-cross-origin")
 			c.Response().Header().Set("Permissions-Policy", "geolocation=(), microphone=(), camera=()")