Add Images admin section for managing source image uses

New top-level nav section showing all source images in a list view
with checkboxes to edit the uses array (grid, bin) per image. Allows
correcting wrongly-tagged images without code changes.

Server PUT /api/source-images/:id was already in place; re-added the
frontend API wrapper that was prematurely removed.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/templates.html

@@ -248,6 +248,27 @@
 	<div class="empty-state"></div>
 </template>
 
+<!-- ===== IMAGES SECTION ===== -->
+<template id="t-section-images">
+	<section class="section" id="section-images">
+		<div class="img-admin-list" id="img-admin-list"></div>
+	</section>
+</template>
+
+<template id="t-img-admin-row">
+	<div class="img-admin-row">
+		<a class="img-admin-thumb-link" target="_blank" rel="noopener">
+			<img class="img-admin-thumb" alt="">
+		</a>
+		<div class="img-admin-info">
+			<div class="img-admin-name"></div>
+			<div class="img-admin-meta"></div>
+			<div class="img-admin-uses"></div>
+		</div>
+		<button type="button" class="btn-icon btn-danger img-admin-delete" title="Delete">✕</button>
+	</div>
+</template>
+
 <!-- ===== GRIDS SECTION ===== -->
 <template id="t-section-grids">
 	<section class="section" id="section-grids">