fix(feed): reduce excess spacing between entries

Removed redundant margin-bottom on .journal-post (feed gap already
separates items). Reduced padding-bottom and gap from 3rem to 2rem,
cutting the between-entry whitespace roughly in half.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vgmzx8VTTTmCskSpQtsLTr

themes/intotheeast/css/style.css

@@ -87,7 +87,7 @@ body::after {
 
 /* ── Feed ────────────────────────────────────────────────────────────────────── */
 
-.feed { display: flex; flex-direction: column; gap: var(--space-12); }
+.feed { display: flex; flex-direction: column; gap: var(--space-8); }
 .feed-empty { color: var(--color-ink-muted); font-style: italic; }
 
 .entry-card {
@@ -95,7 +95,7 @@ body::after {
     text-decoration: none;
     color: inherit;
     border-bottom: 1px solid var(--color-border);
-    padding-bottom: var(--space-12);
+    padding-bottom: var(--space-8);
     transition: background 0.15s;
 }
 
@@ -162,8 +162,7 @@ body::after {
 
 .journal-post {
     border-bottom: 1px solid var(--color-border);
-    padding-bottom: var(--space-12);
-    margin-bottom: var(--space-12);
+    padding-bottom: var(--space-8);
 }
 
 .journal-post-header {