Gallery: photos open lightbox, add project button, watermark our photos

Gallery flow:
- Album covers now open the photo lightbox directly (full album set), while
  the title/"Read the story" link opens the article. Previously the whole card
  linked to the article and photos were only at the bottom of it.
- Each album carries its full photo set in a hidden js-lightbox grid; added
  main.js support for [data-lightbox-target] cover triggers.
- Added the missing main.js include on the gallery page (its lightbox, mobile
  menu and language switcher never ran before).
- Lightbox gained an optional "Read the story ->" button (data-project-url /
  data-project-label) shown only for gallery albums.

Watermark:
- Baked a subtle "(c) msosorg.com" watermark (bottom-right, sized per image)
  into 114 of our own event/community photos. Stock/partner/logo/icon images
  excluded. Clean originals backed up to images/_originals/ (git-ignored); the
  script always re-derives from them so re-runs never stack.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

main.js

@@ -873,11 +873,13 @@ document.addEventListener('DOMContentLoaded', function() {
             '<button type="button" class="lightbox-prev" aria-label="Previous">&#10094;</button>' +
             '<img class="lightbox-img" src="" alt="">' +
             '<button type="button" class="lightbox-next" aria-label="Next">&#10095;</button>' +
+            '<a class="lightbox-project" href="#" hidden></a>' +
             '<div class="lightbox-caption"></div>';
         document.body.appendChild(lb);
 
         var img = lb.querySelector('.lightbox-img');
         var cap = lb.querySelector('.lightbox-caption');
+        var proj = lb.querySelector('.lightbox-project');
         var group = [];
         var idx = 0;
 
@@ -892,6 +894,15 @@ document.addEventListener('DOMContentLoaded', function() {
                 return { full: b.getAttribute('data-full'), caption: b.getAttribute('data-caption') || '' };
             });
             idx = start;
+            // Optional "go to project" link (present on gallery-page albums).
+            var purl = grid.getAttribute('data-project-url');
+            if (purl) {
+                proj.setAttribute('href', purl);
+                proj.textContent = grid.getAttribute('data-project-label') || 'View project';
+                proj.hidden = false;
+            } else {
+                proj.hidden = true;
+            }
             render();
             lb.classList.add('is-open');
             lb.setAttribute('aria-hidden', 'false');
@@ -910,6 +921,13 @@ document.addEventListener('DOMContentLoaded', function() {
                 b.addEventListener('click', function () { open(grid, i); });
             });
         });
+        // Triggers that open a target gallery (e.g. gallery-page album covers).
+        document.querySelectorAll('[data-lightbox-target]').forEach(function (trig) {
+            trig.addEventListener('click', function () {
+                var g = document.getElementById(trig.getAttribute('data-lightbox-target'));
+                if (g) open(g, 0);
+            });
+        });
         lb.querySelector('.lightbox-close').addEventListener('click', close);
         lb.querySelector('.lightbox-prev').addEventListener('click', function () { step(-1); });
         lb.querySelector('.lightbox-next').addEventListener('click', function () { step(1); });