feat(search): viewer progress + completed badges; dropdown to templ

Search results now show where you are in a book: a completed check at
the 0.999 threshold (same cut as the filter status arms), a partial
progress bar along the cover while mid-read, nothing when you never
opened it. Rendered in BookCard (any grid whose adapter loads viewer
progress) and in the header-search dropdown rows.

The progress rides a LEFT JOIN reading_progress on the SAME user_id
param SearchMediaItemsUnified already binds for library visibility —
one requester param, no new wire inputs, row-neutral join (the table
is UNIQUE per media_item+user). SearchMediaItemsUnifiedRow and BookInfo
gain the keys additively (viewer_percentage null when unknown,
library_name empty on feeds that don't load it); contract_pins.md
carries the changelog entry and the pin tests widen in lockstep.

The header dropdown itself migrates off the innerHTML string renderer
in search.ts (a rendering-ownership violation: a templ twin existed via
the HX-Request branch). The input now hx-gets layout=dropdown and swaps
the new templ SearchResults partial — titles/authors highlighted
server-side (escape-first, safe by construction), rows with the same
progress overlays — while a slim Alpine component owns only
client-local state (min-length gating, open/close, keyboard selection,
htmx lifecycle). web/src/rendering-allowlist.txt drops the search.ts
baseline to zero accordingly.

Integration test pins the per-user join (fresh user sees 1.0/0.42/null
on the fixture; the shared admin sees null everywhere — read-only) and
the dropdown partial's overlays/count/row count.

templates/header_templ.go

@@ -717,7 +717,7 @@ func Header(user User, currentPath string) templ.Component {
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
-		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 71, "</button><div class=\"relative flex-1 max-w-xl\"><span class=\"absolute left-3 top-1/2 -translate-y-1/2 pointer-events-none\" style=\"color: var(--text-secondary);\">")
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 71, "</button><div class=\"relative flex-1 max-w-xl\" x-data=\"headerSearch\" @click.outside=\"close()\"><span class=\"absolute left-3 top-1/2 -translate-y-1/2 pointer-events-none\" style=\"color: var(--text-secondary);\">")
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
@@ -725,7 +725,7 @@ func Header(user User, currentPath string) templ.Component {
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
-		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 72, "</span> <input type=\"text\" id=\"header-search\" placeholder=\"Search your library…\" class=\"input pl-10\" autocomplete=\"off\"></div></div></header><!-- module bundle; ?v=<commit-ish stamp> busts stale intermediate\n\t\t     builds across app restarts (browser caches are keyed by URL) --><script type=\"module\" src=\"/static/main.js?v=7\"></script></div>")
+		templ_7745c5c3_Err = templruntime.WriteString(templ_7745c5c3_Buffer, 72, "</span> <input type=\"text\" id=\"header-search\" name=\"q\" placeholder=\"Search your library…\" class=\"input pl-10\" autocomplete=\"off\" x-ref=\"input\" role=\"combobox\" :aria-expanded=\"open ? 'true' : 'false'\" aria-label=\"Search your library\" @input=\"onInput()\" @focus=\"onFocus()\" @keydown.arrow-down.prevent=\"moveSelection(1)\" @keydown.arrow-up.prevent=\"moveSelection(-1)\" @keydown.enter.prevent=\"openSelected()\" @keydown.escape=\"close()\" hx-get=\"/api/media-items/search?layout=dropdown\" hx-trigger=\"search delay:300ms\" hx-target=\"#search-results\" hx-swap=\"innerHTML\"><div id=\"search-results\" x-show=\"open\" x-cloak class=\"absolute z-50 w-full max-w-2xl mt-2 rounded-lg shadow-lg border overflow-hidden\" style=\"background-color: var(--bg-secondary); border-color: var(--border)\"></div></div></div></header><!-- module bundle; ?v=<commit-ish stamp> busts stale intermediate\n\t\t     builds across app restarts (browser caches are keyed by URL) --><script type=\"module\" src=\"/static/main.js?v=7\"></script></div>")
 		if templ_7745c5c3_Err != nil {
 			return templ_7745c5c3_Err
 		}
@@ -770,7 +770,7 @@ func SidebarUserMenu(user User) templ.Component {
 		var templ_7745c5c3_Var43 string
 		templ_7745c5c3_Var43, templ_7745c5c3_Err = templ.JoinStringErrs(user.Username)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/header.templ`, Line: 259, Col: 58}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/header.templ`, Line: 281, Col: 58}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ.EscapeString(templ_7745c5c3_Var43))
 		if templ_7745c5c3_Err != nil {
@@ -854,7 +854,7 @@ func SidebarSignIn(currentPath string) templ.Component {
 		var templ_7745c5c3_Var45 string
 		templ_7745c5c3_Var45, templ_7745c5c3_Err = templ.ResolveAttributeValue(currentPath)
 		if templ_7745c5c3_Err != nil {
-			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/header.templ`, Line: 307, Col: 60}
+			return templ.Error{Err: templ_7745c5c3_Err, FileName: `templates/header.templ`, Line: 329, Col: 60}
 		}
 		_, templ_7745c5c3_Err = templ_7745c5c3_Buffer.WriteString(templ_7745c5c3_Var45)
 		if templ_7745c5c3_Err != nil {