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/e2e/messages.py

@@ -1,6 +1,8 @@
 # retoor <retoor@molodetz.nl>
 
+import re
 import time
+from playwright.sync_api import expect
 from tests.conftest import BASE_URL
 from devplacepy.database import get_table
 import requests
@@ -211,6 +213,49 @@ def test_messages_search_for_bob(alice):
     assert result.is_visible()
 
 
+def test_messages_search_first_result_highlighted(alice):
+    page, _ = alice
+    page.goto(f"{BASE_URL}/messages", wait_until="domcontentloaded")
+    page.fill("#message-search", "bob_test")
+    result = page.locator(".search-dropdown-item:has-text('bob_test')")
+    result.wait_for(state="visible", timeout=5000)
+    expect(result.first).to_have_class(re.compile(r"\bactive\b"))
+
+
+def test_messages_search_enter_opens_conversation(alice):
+    page, _ = alice
+    page.goto(f"{BASE_URL}/messages", wait_until="domcontentloaded")
+    page.fill("#message-search", "bob_test")
+    page.locator(".search-dropdown-item:has-text('bob_test')").wait_for(
+        state="visible", timeout=5000
+    )
+    page.locator("#message-search").press("Enter")
+    page.wait_for_url(re.compile(r"with_uid="), wait_until="domcontentloaded")
+
+
+def test_messages_search_arrow_then_enter_opens_conversation(alice):
+    page, _ = alice
+    page.goto(f"{BASE_URL}/messages", wait_until="domcontentloaded")
+    page.fill("#message-search", "bob_test")
+    page.locator(".search-dropdown-item:has-text('bob_test')").wait_for(
+        state="visible", timeout=5000
+    )
+    search = page.locator("#message-search")
+    search.press("ArrowDown")
+    search.press("Enter")
+    page.wait_for_url(re.compile(r"with_uid="), wait_until="domcontentloaded")
+
+
+def test_messages_search_escape_closes_dropdown(alice):
+    page, _ = alice
+    page.goto(f"{BASE_URL}/messages", wait_until="domcontentloaded")
+    page.fill("#message-search", "bob_test")
+    result = page.locator(".search-dropdown-item:has-text('bob_test')")
+    result.wait_for(state="visible", timeout=5000)
+    page.locator("#message-search").press("Escape")
+    expect(result).to_be_hidden()
+
+
 def test_messages_header_visible(alice):
     page, _ = alice
     page.goto(f"{BASE_URL}/messages", wait_until="domcontentloaded")