feat(cot): add CFTC Traders-in-Financial-Futures adapter (M22 slice 7)

Parse the annual FinFutYY.txt zip (leveraged-funds long/short + OI) into a
CotSeries. Registers the 'cot' source_kind, 'cot_weekly' TTL (7d), the 'cftc'
vendor family (1 req/1.5s pacing), and the adapter in the queue registry.

Uses the file-header column names so parser is robust to layout changes.

app/server/src/cache/CacheRepository.ts

@@ -12,14 +12,14 @@ import {
 } from '../queue/sourceRatePolicy.ts';
 import { KvReadCache } from './LruCache.ts';
 
-export type SourceKind = 'yfinance' | 'nasdaq' | 'finra-bulk' | 'finra-si' | 'sec' | 'sec-fetch' | 'sec-sc-fetch' | 'sec-tickers' | 'reddit' | 'x' | 'macro' | 'llm' | 'sec-lint-holders' | 'sec-lint-insiders' | 'fred';
+export type SourceKind = 'yfinance' | 'nasdaq' | 'finra-bulk' | 'finra-si' | 'sec' | 'sec-fetch' | 'sec-sc-fetch' | 'sec-tickers' | 'reddit' | 'x' | 'macro' | 'llm' | 'sec-lint-holders' | 'sec-lint-insiders' | 'fred' | 'cot';
 export type TickerKind = 'equity' | 'crypto' | 'etf' | 'index';
 export type CacheKey = string; // `${SourceKind}:${kind}:${id}` e.g. 'yfinance:quote:NVDA', 'yfinance:candles:NVDA:1d'
 export type TtlClass =
   | 'live_quote' | 'intraday' | 'daily_permanent' | 'options_snapshot'
   | 'filing_immutable' | 'quarterly_immutable' | 'thread_7d'
   | 'macro_event' | 'regime_classification' | 'llm_summary' | 'symbol_meta'
-  | 'short_interest' | 'dividend_fundamentals' | 'fred_macro';
+  | 'short_interest' | 'dividend_fundamentals' | 'fred_macro' | 'cot_weekly';
 
 export interface Provenance { fetchedAt: string; sourceKind: SourceKind; rawSourceId?: string; }
 
@@ -68,6 +68,7 @@ export const TTL_MS: Record<TtlClass, number> = {
   short_interest: 24 * 60 * 60_000,      // refreshed twice/month per source
   dividend_fundamentals: 7 * 24 * 60 * 60_000, // weekly (yield/payout change slowly)
   fred_macro: 24 * 60 * 60_000,          // daily (rates move daily; other series slower)
+  cot_weekly: 7 * 24 * 60 * 60_000,      // COT arrives weekly on Fridays
 };
 
 /** Parse 'source:kind:id...' into { source, kind, id } (id may contain colons). */