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

tests/api/admin/aiusage/index.py

@@ -18,7 +18,7 @@ def _admin_aiusage(seeded_db):
 
 def test_admin_ai_usage_page_requires_admin(app_server):
     r = requests.get(f"{BASE_URL}/admin/ai-usage", allow_redirects=False)
-    assert r.status_code in (302, 401, 403)
+    assert r.status_code in (302, 303, 401, 403)
 
 
 def test_admin_ai_usage_page_returns_html(app_server, seeded_db):

tests/api/admin/backups/download.py

@@ -4,7 +4,12 @@ import time
 import requests
 from tests.conftest import BASE_URL
 from devplacepy import config
-from devplacepy.database import get_table, get_primary_admin_uid, refresh_snapshot
+from devplacepy.database import (
+    get_table,
+    get_primary_admin_uid,
+    invalidate_admins_cache,
+    refresh_snapshot,
+)
 from devplacepy.services.backup import store
 from devplacepy.utils import clear_user_cache
 
@@ -33,6 +38,7 @@ def _make_admin():
     row = _signup()
     get_table("users").update({"uid": row["uid"], "role": "Admin"}, ["uid"])
     clear_user_cache(row["uid"])
+    invalidate_admins_cache()
     return row["api_key"]