feat: short interest panel Phase 1 Yahoo Finance

- Add short_interest TtlClass (24h) to CacheRepository.ts with shortInterestHandler KindHandler (kv_cache JSON pattern), register in HANDLERS and del switch case
- Add case 'shortinterest' to YFinanceAdapter.fetchOne using quoteSummary(defaultKeyStatistics): parses sharesShort, shortPercentOfFloat, shortRatio, dateShortInterest, sharesShortPriorMonth, floatShares, sharesOutstanding
- Add institutional.shortInterest tRPC procedure (cache-read pattern, returns stale flag + provenance)
- Add api.institutional.shortInterest to frontend trpc client
- Create ShortInterestPanel.tsx: mirrors AnalystRatings pattern with loading/error/retry states, formatted shares/ratio/percentage display with source date
- Mount ShortInterestPanel on overview page after AnalystRatings

app/server/src/cache/CacheRepository.ts

@@ -12,7 +12,8 @@ export type CacheKey = string; // `${SourceKind}:${kind}:${id}` e.g. 'yfinance:q
 export type TtlClass =
   | 'live_quote' | 'intraday' | 'daily_permanent' | 'options_snapshot'
   | 'filing_immutable' | 'quarterly_immutable' | 'thread_7d'
-  | 'macro_event' | 'regime_classification' | 'llm_summary' | 'symbol_meta';
+  | 'macro_event' | 'regime_classification' | 'llm_summary' | 'symbol_meta'
+  | 'short_interest';
 
 export interface Provenance { fetchedAt: string; sourceKind: SourceKind; rawSourceId?: string; }
 
@@ -38,6 +39,7 @@ export const TTL_MS: Record<TtlClass, number> = {
   regime_classification: 24 * 60 * 60_000,
   llm_summary: Number.POSITIVE_INFINITY,    // cached forever by prompt-hash
   symbol_meta: 7 * 24 * 60 * 60_000,         // weekly (slow-changing sector/industry)
+  short_interest: 24 * 60 * 60_000,      // refreshed twice/month per source
 };
 
 /** Parse 'source:kind:id...' into { source, kind, id } (id may contain colons). */
@@ -280,11 +282,24 @@ const lintHoldersHandler: KindHandler = {
 
 const lintInsidersHandler: KindHandler = {
   ttlClass: 'daily_permanent',
-  read() { return null; }, // never read — work happens in DB tables directly
+  read() { return null; },
   write(d, key, _value, provenance) {
     d.prepare('INSERT OR REPLACE INTO kv_cache (key,value,observed_at) VALUES (?,?,?)').run(`sec-lint-insiders:${key}`, JSON.stringify({ ok: true }), provenance.fetchedAt);
   },
-  isStale() { return false; }, // never stale once written
+  isStale() { return false; },
+};
+
+const shortInterestHandler: KindHandler = {
+  ttlClass: 'short_interest',
+  read(d, id) {
+    const r = d.prepare('SELECT value, observed_at FROM kv_cache WHERE key=?').get(`yfinance:shortinterest:${id}`) as { value: string; observed_at: string } | undefined;
+    if (!r) return null;
+    try { return { value: JSON.parse(r.value), stalenessTs: r.observed_at }; } catch { return null; }
+  },
+  write(d, id, value, provenance) {
+    d.prepare('INSERT OR REPLACE INTO kv_cache (key, value, observed_at) VALUES (?,?,?)').run(`yfinance:shortinterest:${id}`, JSON.stringify(value), provenance.fetchedAt);
+  },
+  isStale(ts, now) { return tsAgeMs(ts, now) > TTL_MS.short_interest; },
 };
 
 const HANDLERS = new Map<string, KindHandler>([
@@ -298,6 +313,7 @@ const HANDLERS = new Map<string, KindHandler>([
   ['fetch', fetchHandler],
   ['holders', lintHoldersHandler],
   ['insiders', lintInsidersHandler],
+  ['shortinterest', shortInterestHandler],
 ]);
 
 export interface CacheRepository {
@@ -405,6 +421,9 @@ export class CacheRepositoryImpl implements CacheRepository {
       case 'expiry_dates':
         d.prepare('DELETE FROM kv_cache WHERE key=?').run(`options_expiry:${id}`);
         break;
+      case 'shortinterest':
+        d.prepare('DELETE FROM kv_cache WHERE key=?').run(`yfinance:shortinterest:${id}`);
+        break;
       default: {
         // Unknown/wildcard kind (e.g. `x:cashtag:*`): best-effort delete from kv_cache via LIKE.
         const like = key.endsWith(':*') ? `${key.slice(0, -1)}%` : key;