feat: web dashboard and playground work

The NexusDashboard-parity dashboard (dDashboardServer) and everything built on it on the experimental branch:
accounts, characters, properties and moderation tools, permissions shared with in-game slash commands, economy
reports, World 3D and property 3D views with client scenery, scheduled events (features, vanity changes, live
events, announcements, restarts), vanity files and events, the CDClient browser, the message inspector with saved
captures, chat filter tools, community challenges, live ops, the AI moderator helper, and the server-side changes
they need.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

migrations/dlu/sqlite/13_account_email.sql

@@ -0,0 +1,13 @@
+/* Account email for password resets. Column names match NexusDashboard. */
+ALTER TABLE accounts ADD COLUMN email TEXT DEFAULT '';
+ALTER TABLE accounts ADD COLUMN email_confirmed_at DATETIME DEFAULT NULL;
+/* Sessions issued before this unix time are rejected, e.g. after a password reset */
+ALTER TABLE accounts ADD COLUMN sessions_valid_after BIGINT NOT NULL DEFAULT 0;
+CREATE TABLE IF NOT EXISTS account_tokens (
+    token_hash TEXT NOT NULL PRIMARY KEY,
+    account_id INTEGER NOT NULL,
+    purpose TEXT NOT NULL,
+    data TEXT NOT NULL DEFAULT '',
+    expires_at BIGINT NOT NULL
+);
+CREATE INDEX IF NOT EXISTS account_tokens_account ON account_tokens (account_id, purpose);