activity: sort, load more, compromises for client-side search

my initial intent before starting search was for it to be server-sided,
considering this activity log could rack up 100s or 1000s of entries,
and then I forgot and did it client-sided.

this commit adds a feature to load more results when scrolled to the
bottom, and when a search returns few or no results (this is limited, so
it wont loop infinitely). Also finally got rid of the useless left
column, since my ideas didn't match my implementation.

also, sorting is only by date, can't be bothered with anything else.

css/loader.css

@@ -3,6 +3,10 @@
     color: rgba(0, 0, 0, 0) !important;
 }
 
+.loader.rel {
+    position: relative;
+}
+
 .loader .dot {
     --diameter: 0.5rem;
     --radius: calc(var(--diameter) / 2);
@@ -15,6 +19,12 @@
     left: calc(50% - var(--radius));
     animation: osc 1s cubic-bezier(.72,.16,.31,.97) infinite;
 }
+
+.loader.rel .dot {
+    position: absolute;
+    top: 50%;
+}
+
 .loader.loader-sm .dot {
     --deviation: 10%;
 }