docs: add block/mute user relations, emoji-sync CLI, and uid indexes

- Add `/block`, `/mute` endpoints with block/unblock and mute/unmute functionality in `routers/relations.py`, hiding blocked users' content everywhere except their own profile while muting only suppresses notifications
- Introduce `devplace emoji-sync` CLI command to regenerate `static/js/emoji-shortcodes.js` from the emoji library, documented in `CLAUDE.md` and wired in `cli.py`
- Create `get_blocked_uids()` database helper and apply it in `content.py` `load_detail()` to filter blocked users' posts from detail views
- Implement `_uid_index()` and `_drop_index()` helpers in `database.py` for unique uid indexes across tables, with `user_relations` added to `SOFT_DELETE_TABLES`
- Document new routes in `AGENTS.md` and `README.md`, including emoji shortcodes rendering behavior distinct from the emoji picker

devplacepy/static/css/base.css

@@ -562,9 +562,6 @@ img {
 }
 .topnav-link:hover { color: var(--text-primary); background: var(--bg-card); }
 .topnav-link.active { color: var(--accent); background: var(--accent-light); }
-.topnav-link.topnav-link-feature { color: var(--accent); font-weight: 600; background: var(--accent-light); }
-.topnav-link.topnav-link-feature:hover { color: var(--accent); background: var(--accent-light); filter: brightness(1.2); }
-.topnav-link.topnav-link-feature.active { color: var(--white); background: var(--accent-gradient); box-shadow: var(--glow-accent); }
 .topnav-right { margin-left: auto; display: flex; align-items: center; gap: 1rem; flex-shrink: 0; }
 .topnav-icon { position: relative; padding: 0.375rem; color: var(--text-secondary); font-size: 1.25rem; background: none; border: none; cursor: pointer; font-family: inherit; line-height: 1; }
 .topnav-icon:hover { color: var(--text-primary); }
@@ -1064,6 +1061,36 @@ body:has(.page-messages) {
     border: 0;
 }
 
+.skip-link {
+    position: absolute;
+    top: 0;
+    left: 0;
+    z-index: 2000;
+    transform: translateY(-150%);
+    padding: 0.75rem 1.25rem;
+    background: var(--accent);
+    color: #fff;
+    border-radius: 0 0 var(--radius-input) 0;
+    font-weight: 600;
+    text-decoration: none;
+    transition: transform 0.15s ease;
+}
+
+.skip-link:focus {
+    transform: translateY(0);
+    outline: 2px solid #fff;
+    outline-offset: 2px;
+}
+
+:focus-visible {
+    outline: 2px solid var(--accent);
+    outline-offset: 2px;
+}
+
+[inert] {
+    pointer-events: none;
+}
+
 
 @media (max-width: 1024px) {
     .topnav-links {
@@ -1220,12 +1247,6 @@ body:has(.page-messages) {
     opacity: 0.55;
 }
 
-.login-hint {
-    font-size: 0.8125rem;
-    color: var(--text-muted);
-    text-decoration: underline;
-}
-
 .response-time-indicator {
     position: fixed;
     left: 0.5rem;

devplacepy/static/css/messages.css

@@ -63,7 +63,8 @@
     text-decoration: none;
 }
 
-.search-dropdown-item:hover {
+.search-dropdown-item:hover,
+.search-dropdown-item.active {
     background: var(--bg-card-hover);
 }