fix(podcasts): library switcher leaked literal "continue" and the podcasts option

The D13 podcast exclusion (9a148c23) was written as a templ
`if !IsBookLibrary(...) { continue }` — but templ markup control flow
has NO continue STATEMENT: codegen emitted the word as a TEXT node
(visible junk between options on every page's library subbar) and
rendered the podcasts option anyway, defeating the exclusion. The real
browser sweep caught what every Go/API test structurally cannot:
generated markup that renders wrong yet compiles clean.

Rewritten as an inverted guard (the idiomatic templ skip). New render
pin TestLibrarySwitcherExcludesPodcasts fails on both halves of the
original leak — the literal text AND the presence of the podcasts
option — so this codegen gotcha class stays tripped-wired.

templates/library_switcher.templ

@@ -30,19 +30,22 @@ templ LibrarySwitcher(libData []LibraryData, currentLibraryID string, title stri
 					// in the book-library switcher — feeds surface via
 					// /podcasts only. Presentation-layer filter so every
 					// switcher consumer is correct at once.
-					if !IsBookLibrary(lib.TypeName) {
-						continue
-					}
-					if lib.Offline {
-						if lib.ID == currentLibraryID {
-							<option value={ lib.ID } selected>{ lib.Name } ({ lib.MediaCount }) — storage offline</option>
+					// (templ markup control flow has NO `continue`
+					// statement — codegen emits it as literal TEXT and
+					// renders the option anyway, browser-sweep finding
+					// 2026-10-30; keep the skip as an inverted guard.)
+					if IsBookLibrary(lib.TypeName) {
+						if lib.Offline {
+							if lib.ID == currentLibraryID {
+								<option value={ lib.ID } selected>{ lib.Name } ({ lib.MediaCount }) — storage offline</option>
+							} else {
+								<option value={ lib.ID }>{ lib.Name } ({ lib.MediaCount }) — storage offline</option>
+							}
+						} else if lib.ID == currentLibraryID {
+							<option value={ lib.ID } selected>{ lib.Name } ({ lib.MediaCount })</option>
 						} else {
-							<option value={ lib.ID }>{ lib.Name } ({ lib.MediaCount }) — storage offline</option>
+							<option value={ lib.ID }>{ lib.Name } ({ lib.MediaCount })</option>
 						}
-					} else if lib.ID == currentLibraryID {
-						<option value={ lib.ID } selected>{ lib.Name } ({ lib.MediaCount })</option>
-					} else {
-						<option value={ lib.ID }>{ lib.Name } ({ lib.MediaCount })</option>
 					}
 				}
 				</select>