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/js/Application.js

@@ -37,9 +37,11 @@ import { ContainerTerminalManager } from "./ContainerTerminalManager.js";
 import { PubSubClient } from "./PubSubClient.js";
 import { LiveNotifications } from "./LiveNotifications.js";
 import { LocalTime } from "./LocalTime.js";
+import { Accessibility } from "./Accessibility.js";
 
 class Application {
     constructor() {
+        this.accessibility = new Accessibility();
         this.dialog = document.createElement("dp-dialog");
         this.contextMenu = document.createElement("dp-context-menu");
         this.toast = document.createElement("dp-toast");