docs: add vulgar-word/fragment-sold reserved-username lists and CSVs, reserve script

Extends the reserved-usernames doc with a vulgar/offensive section, adds
CSV exports (username,reason) for both the categorized reserved-usernames
list and a filtered snapshot of fragment.com's sold usernames, and adds a
scripts/reserve_usernames.py CLI to bulk-feed a CSV into the admin panel's
reserved-usernames blocklist via the real login -> CSRF -> reserve-username
API flow.

docs/reserved-usernames.csv

@@ -0,0 +1,102 @@
+telegram,official-sounding / staff-impersonation
+telegramofficial,official-sounding / staff-impersonation
+telegramsupport,official-sounding / staff-impersonation
+telegramteam,official-sounding / staff-impersonation
+telegramstaff,official-sounding / staff-impersonation
+telegramhq,official-sounding / staff-impersonation
+telegramnews,official-sounding / staff-impersonation
+telegramnotifications,official-sounding / staff-impersonation
+telegramverify,official-sounding / staff-impersonation
+telegrambot,official-sounding / staff-impersonation
+telegramservice,official-sounding / staff-impersonation
+security,official-sounding / staff-impersonation
+securityteam,official-sounding / staff-impersonation
+verify,official-sounding / staff-impersonation
+verification,official-sounding / staff-impersonation
+verified,official-sounding / staff-impersonation
+helpdesk,official-sounding / staff-impersonation
+helpcenter,official-sounding / staff-impersonation
+customerservice,official-sounding / staff-impersonation
+customersupport,official-sounding / staff-impersonation
+servicedesk,official-sounding / staff-impersonation
+service,official-sounding / staff-impersonation
+system,official-sounding / staff-impersonation
+systemmessage,official-sounding / staff-impersonation
+systembot,official-sounding / staff-impersonation
+notifications,official-sounding / staff-impersonation
+notification,official-sounding / staff-impersonation
+alerts,official-sounding / staff-impersonation
+announcements,official-sounding / staff-impersonation
+announcement,official-sounding / staff-impersonation
+newsroom,official-sounding / staff-impersonation
+press,official-sounding / staff-impersonation
+pressoffice,official-sounding / staff-impersonation
+spambot,official-sounding / staff-impersonation
+antispam,official-sounding / staff-impersonation
+abuse,official-sounding / staff-impersonation
+abusereport,official-sounding / staff-impersonation
+reports,official-sounding / staff-impersonation
+legal,official-sounding / staff-impersonation
+compliance,official-sounding / staff-impersonation
+billing,official-sounding / staff-impersonation
+payments,official-sounding / staff-impersonation
+finance,official-sounding / staff-impersonation
+accounts,official-sounding / staff-impersonation
+accountservices,official-sounding / staff-impersonation
+recovery,official-sounding / staff-impersonation
+unlock,official-sounding / staff-impersonation
+restore,official-sounding / staff-impersonation
+backup,official-sounding / staff-impersonation
+headquarters,official-sounding / staff-impersonation
+staffteam,official-sounding / staff-impersonation
+modteam,official-sounding / staff-impersonation
+moderation,official-sounding / staff-impersonation
+moderators,official-sounding / staff-impersonation
+founder,official-sounding / staff-impersonation
+cofounder,official-sounding / staff-impersonation
+management,official-sounding / staff-impersonation
+durov,impersonates real Telegram leadership
+pavel,impersonates real Telegram leadership
+paveldurov,impersonates real Telegram leadership
+pdurov,impersonates real Telegram leadership
+nikolai,impersonates real Telegram leadership
+nikolaidurov,impersonates real Telegram leadership
+ndurov,impersonates real Telegram leadership
+durovpavel,impersonates real Telegram leadership
+telegramceo,impersonates real Telegram leadership
+telegramfounder,impersonates real Telegram leadership
+bitcoin,crypto / scam-bait impersonation
+ethereum,crypto / scam-bait impersonation
+toncoin,crypto / scam-bait impersonation
+tonwallet,crypto / scam-bait impersonation
+tonfoundation,crypto / scam-bait impersonation
+crypto,crypto / scam-bait impersonation
+cryptowallet,crypto / scam-bait impersonation
+wallet,crypto / scam-bait impersonation
+airdrop,crypto / scam-bait impersonation
+giveaway,crypto / scam-bait impersonation
+bonus,crypto / scam-bait impersonation
+freecoins,crypto / scam-bait impersonation
+claim,crypto / scam-bait impersonation
+claimnow,crypto / scam-bait impersonation
+binance,crypto / scam-bait impersonation
+coinbase,crypto / scam-bait impersonation
+kraken,crypto / scam-bait impersonation
+metamask,crypto / scam-bait impersonation
+trustwallet,crypto / scam-bait impersonation
+ledger,crypto / scam-bait impersonation
+opensea,crypto / scam-bait impersonation
+uniswap,crypto / scam-bait impersonation
+elonmusk,crypto / scam-bait impersonation
+tesla,crypto / scam-bait impersonation
+spacex,crypto / scam-bait impersonation
+cryptosupport,crypto / scam-bait impersonation
+walletsupport,crypto / scam-bait impersonation
+tonsupport,crypto / scam-bait impersonation
+binancesupport,crypto / scam-bait impersonation
+investment,crypto / scam-bait impersonation
+investmentteam,crypto / scam-bait impersonation
+forextrading,crypto / scam-bait impersonation
+tradingbot,crypto / scam-bait impersonation
+signals,crypto / scam-bait impersonation
+cryptosignals,crypto / scam-bait impersonation