Add bins feature: upload, de-perspective, gallery

- lib/storage.mjs: bin CRUD with bin: prefix
- lib/grid-image.mjs: compute_bin_size() capped at 1024px
- server.mjs: POST/GET/PUT/DELETE /api/bins routes; PUT /api/bins/:id/corners
  re-processes image via process_grid_image with rows=1 cols=1
- public/lib/api.mjs: bin API wrappers including upload_bin()
- public/index.html: Bins nav button
- public/templates.html: t-section-bins, t-bin-card, t-dialog-bin-editor
- public/app.mjs: render_bins(), open_bin_editor() using Grid_Setup,
  save/cancel wiring in init()
- public/style.css: bin gallery and card styles

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

public/style.css

@@ -1085,12 +1085,52 @@ nav {
 	box-shadow: 0 0 0 3px rgba(91, 156, 246, 0.3);
 }
 
+.source-card-footer {
+	display: flex;
+	align-items: center;
+	justify-content: space-between;
+	gap: 0.25rem;
+}
+
 .source-card-meta {
 	font-size: 0.75rem;
 	color: var(--text-faint);
 	overflow: hidden;
 	text-overflow: ellipsis;
 	white-space: nowrap;
+	flex: 1;
+}
+
+.source-card-uses {
+	display: flex;
+	gap: 0.2rem;
+	flex-shrink: 0;
+}
+
+.source-use-badge {
+	font-size: 0.65rem;
+	padding: 0.1rem 0.35rem;
+	border-radius: 3px;
+	text-transform: lowercase;
+	font-weight: 600;
+	letter-spacing: 0.02em;
+	cursor: pointer;
+	border: none;
+	transition: opacity 0.1s;
+}
+
+.source-use-badge.source-use-inactive {
+	opacity: 0.25;
+}
+
+.source-use-grid {
+	background: rgba(91, 156, 246, 0.18);
+	color: #5b9cf6;
+}
+
+.source-use-bin {
+	background: rgba(91, 246, 156, 0.18);
+	color: #5bf69c;
 }
 
 .source-card-delete {
@@ -1806,3 +1846,75 @@ nav {
 .detail-file-link:hover {
 	text-decoration: underline;
 }
+
+/* ===== BINS ===== */
+
+.bin-gallery {
+	display: flex;
+	flex-wrap: wrap;
+	gap: 1rem;
+	padding: 1rem 0;
+}
+
+.bin-card {
+	width: 220px;
+	background: var(--surface);
+	border: 1px solid var(--border);
+	border-radius: 6px;
+	overflow: hidden;
+	display: flex;
+	flex-direction: column;
+}
+
+.bin-card-img-wrap {
+	width: 100%;
+	aspect-ratio: 4 / 3;
+	background: #1a1a1a;
+	position: relative;
+	overflow: hidden;
+}
+
+.bin-card-img {
+	width: 100%;
+	height: 100%;
+	object-fit: contain;
+	display: block;
+}
+
+.bin-card-unprocessed {
+	position: absolute;
+	inset: 0;
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	font-size: 0.75rem;
+	color: var(--text-muted);
+	background: rgba(0,0,0,0.5);
+}
+
+.bin-card-img-wrap.has-image .bin-card-unprocessed {
+	display: none;
+}
+
+.bin-card-footer {
+	display: flex;
+	align-items: center;
+	justify-content: space-between;
+	padding: 0.4rem 0.5rem;
+	gap: 0.5rem;
+	min-height: 2rem;
+}
+
+.bin-card-name {
+	font-size: 0.85rem;
+	overflow: hidden;
+	text-overflow: ellipsis;
+	white-space: nowrap;
+	flex: 1;
+}
+
+.bin-editor-canvas {
+	display: block;
+	border-radius: 4px;
+	max-width: 100%;
+}