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/dashboard.templ

@@ -144,7 +144,7 @@ templ BookCard(item handlers.BookInfo) {
 					/>
 				}
 				<!-- Media-type identifier (A2c): books stay unbadged — the
-				     shelf default already reads as a book -->
+			     shelf default already reads as a book -->
 				if MediaBadgeIcon(item.Badge) != "" {
 					<span
 						class="absolute top-2 right-2 z-10 flex items-center justify-center h-7 w-7 rounded-full shadow-sm"
@@ -154,6 +154,25 @@ templ BookCard(item handlers.BookInfo) {
 						@Icon(MediaBadgeIcon(item.Badge), "h-4 w-4")
 					</span>
 				}
+				<!-- Viewer progress (2026-10-27 search-progress batch):
+				     completed check top-left, partial bar along the cover
+				     bottom. Renders only when the feeding adapter loaded
+				     the requester's progress (search today). -->
+				if item.ViewerPercentage != nil {
+					if *item.ViewerPercentage >= CompletedProgressThreshold {
+						<span
+							class="absolute top-2 left-2 z-10 flex items-center justify-center h-7 w-7 rounded-full shadow-sm"
+							style="background-color: color-mix(in srgb, var(--bg-primary) 78%, transparent); color: var(--accent); backdrop-filter: blur(3px);"
+							title="Completed"
+						>
+							@Icon("check", "h-4 w-4")
+						</span>
+					} else if *item.ViewerPercentage > 0 {
+						<div class="absolute bottom-0 left-0 right-0 z-10 h-1" style="background-color: color-mix(in srgb, var(--bg-primary) 55%, transparent);">
+							<div class="h-full" style={ progressFillCSS(*item.ViewerPercentage) }></div>
+						</div>
+					}
+				}
 			</div>
 			<div class="book-card-meta">
 				<h3 class="font-semibold text-sm leading-snug line-clamp-2" style="color: var(--text-primary)" title={ item.Title }>