Add aspect-ratio-aware image galleries

This adds a project-local gallery plugin that builds deterministic rectangular
image layouts from attachment aspect ratios, with both in-process and disk-backed
layout caching.

It also adds gallery flow blocks, templates, and CSS so posts can include
responsive galleries with lazy-loaded images, configurable gaps, target ratios,
and the existing breakout/centering utilities.

1 files changed, 9 insertions, 0 deletions

diff --git a/templates/blocks/gallery-image.html b/templates/blocks/gallery-image.html
new file mode 100644
index 0000000..44a8e93
--- /dev/null
+++ b/templates/blocks/gallery-image.html
@@ -0,0 +1,9 @@
+{% set image = record.attachments.get(this["image"]) %}
+{% if image %}
+  <img src="{{ image | url }}"
+       width="{{ image.width }}"
+       height="{{ image.height }}"
+       alt="{{ this["alt"] }}"
+       loading="lazy"
+       decoding="async">
+{% endif %}