fix: client perms, @everyone/@channel, docs, unit tests

- usePermissions ORs current user roles + @everyone only (not all server roles)
- cache myRolesByServer; load on active server; refresh after self role edit
- gate/notify @everyone and @channel; plain @username push; special mention UI
- refresh FEATURE_PARITY (DMs exist; drop stale critical gaps)
- README production deploy notes dumpster.service
- unit tests for permission bits and broadcast mention tokens

web/src/components/MentionDropdown.tsx

@@ -1,52 +1,112 @@
 import type { Member } from "../stores/member.ts";
 
+export type MentionOption =
+  | { kind: "special"; id: string; label: string; description: string }
+  | { kind: "user"; member: Member };
+
 interface MentionDropdownProps {
   query: string;
   members: Member[];
   selectedIndex: number;
   onSelect: (username: string) => void;
+  canMentionEveryone?: boolean;
 }
 
-export function MentionDropdown({ query, members, selectedIndex, onSelect }: MentionDropdownProps) {
+const SPECIALS: { id: string; label: string; description: string }[] = [
+  { id: "everyone", label: "everyone", description: "Notify the entire server" },
+  { id: "channel", label: "channel", description: "Notify everyone in this channel" },
+];
+
+export function buildMentionOptions(
+  query: string,
+  members: Member[],
+  canMentionEveryone: boolean,
+): MentionOption[] {
   const q = query.toLowerCase();
-  const filtered = members
+  const options: MentionOption[] = [];
+
+  if (canMentionEveryone) {
+    for (const s of SPECIALS) {
+      if (!q || s.id.startsWith(q) || s.label.startsWith(q)) {
+        options.push({ kind: "special", id: s.id, label: s.label, description: s.description });
+      }
+    }
+  }
+
+  const users = members
     .filter(
       (m) =>
         m.username.toLowerCase().includes(q) ||
         m.display_name?.toLowerCase().includes(q),
     )
-    .slice(0, 6);
+    .slice(0, 6)
+    .map((m): MentionOption => ({ kind: "user", member: m }));
 
-  if (filtered.length === 0) return null;
+  return [...options, ...users].slice(0, 8);
+}
+
+export function MentionDropdown({
+  query,
+  members,
+  selectedIndex,
+  onSelect,
+  canMentionEveryone = false,
+}: MentionDropdownProps) {
+  const options = buildMentionOptions(query, members, canMentionEveryone);
+
+  if (options.length === 0) return null;
 
   return (
-    <div className="absolute bottom-full left-0 mb-1 z-50 w-64 max-h-48 overflow-y-auto bg-gb-bg-s border border-gb-bg-t shadow-lg">
+    <div className="absolute bottom-full left-0 mb-1 z-50 w-72 max-h-48 overflow-y-auto bg-gb-bg-s border border-gb-bg-t shadow-lg">
       <div className="px-2 py-1 text-xs text-gb-fg-s font-mono border-b border-gb-bg-t">
         MENTION
       </div>
-      {filtered.map((m, i) => (
-        <button
-          key={m.id}
-          type="button"
-          onMouseDown={(e) => {
-            e.preventDefault();
-            onSelect(m.username);
-          }}
-          className={`w-full px-2 py-1 text-left text-sm font-mono flex items-center gap-2 transition-colors ${
-            i === selectedIndex
-              ? "bg-gb-orange text-gb-bg"
-              : "hover:bg-gb-orange hover:text-gb-bg"
-          }`}
-        >
-          <span className={i === selectedIndex ? "text-gb-bg" : "text-gb-green"}>●</span>
-          <span className="truncate">{m.display_name || m.username}</span>
-          {m.display_name && m.display_name !== m.username && (
-            <span className={`text-xs ${i === selectedIndex ? "text-gb-bg" : "text-gb-fg-f"}`}>
-              ({m.username})
-            </span>
-          )}
-        </button>
-      ))}
+      {options.map((opt, i) => {
+        const active = i === selectedIndex;
+        if (opt.kind === "special") {
+          return (
+            <button
+              key={opt.id}
+              type="button"
+              onMouseDown={(e) => {
+                e.preventDefault();
+                onSelect(opt.label);
+              }}
+              className={`w-full px-2 py-1.5 text-left text-sm font-mono flex items-center gap-2 transition-colors ${
+                active ? "bg-gb-orange text-gb-bg" : "hover:bg-gb-orange hover:text-gb-bg"
+              }`}
+            >
+              <span className={active ? "text-gb-bg" : "text-gb-orange"}>@</span>
+              <span className="font-bold">{opt.label}</span>
+              <span className={`text-xs truncate ${active ? "text-gb-bg" : "text-gb-fg-f"}`}>
+                {opt.description}
+              </span>
+            </button>
+          );
+        }
+        const m = opt.member;
+        return (
+          <button
+            key={m.id}
+            type="button"
+            onMouseDown={(e) => {
+              e.preventDefault();
+              onSelect(m.username);
+            }}
+            className={`w-full px-2 py-1 text-left text-sm font-mono flex items-center gap-2 transition-colors ${
+              active ? "bg-gb-orange text-gb-bg" : "hover:bg-gb-orange hover:text-gb-bg"
+            }`}
+          >
+            <span className={active ? "text-gb-bg" : "text-gb-green"}>●</span>
+            <span className="truncate">{m.display_name || m.username}</span>
+            {m.display_name && m.display_name !== m.username && (
+              <span className={`text-xs ${active ? "text-gb-bg" : "text-gb-fg-f"}`}>
+                ({m.username})
+              </span>
+            )}
+          </button>
+        );
+      })}
     </div>
   );
 }