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/adapters/YFinanceAdapter.ts

@@ -45,6 +45,34 @@ export class YFinanceAdapter implements SourceFetch {
         const raw = await yf.quoteSummary(id, { modules: ['summaryProfile'] });
         return { value: parseSymbol(raw, id), ttlClass: 'symbol_meta', provenance: { fetchedAt, sourceKind: 'yfinance', rawSourceId: id } };
       }
+      case 'shortinterest': {
+        const raw = await yf.quoteSummary(id, { modules: ['defaultKeyStatistics'] });
+        const stats = (raw as Record<string, unknown>)?.defaultKeyStatistics as Record<string, unknown> | undefined;
+        if (!stats) throw new Error('No defaultKeyStatistics module available');
+        const parseNum = (v: unknown): number | null => {
+          if (v === null || v === undefined) return null;
+          if (typeof v === 'number') return v;
+          const s = String(v).replace(/[,]/g, '');
+          const n = parseFloat(s);
+          return Number.isNaN(n) ? null : n;
+        };
+        return {
+          value: {
+            sharesShort: parseNum(stats.sharesShort),
+            sharesShortPriorMonth: parseNum(stats.sharesShortPriorMonth),
+            sharesShortPreviousMonthDate: stats.sharesShortPreviousMonthDate ? String(stats.sharesShortPreviousMonthDate).slice(0, 10) : null,
+            dateShortInterest: stats.dateShortInterest ? String(stats.dateShortInterest).slice(0, 10) : null,
+            sharesPercentSharesOut: parseNum(stats.sharesPercentSharesOut),
+            shortRatio: parseNum(stats.shortRatio),
+            shortPercentOfFloat: parseNum(stats.shortPercentOfFloat),
+            floatShares: parseNum(stats.floatShares),
+            sharesOutstanding: parseNum(stats.sharesOutstanding),
+            sourceTickerKind: (stats as Record<string, unknown>).optionMethod?.toString() ?? null,
+          },
+          ttlClass: 'short_interest',
+          provenance: { fetchedAt, sourceKind: 'yfinance', rawSourceId: id },
+        };
+      }
       default: throw new Error(`YFinanceAdapter: unknown kind '${kind}'`);
     }
   }

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;

app/server/src/trpc/router.ts

@@ -1897,9 +1897,32 @@ const institutionalRouter = router({
         if (cached) return { symbol, ratings: cached.ratings, consensus: cached.consensus, stale: true };
         return { symbol, ratings: [], consensus: null, error: result.error };
       }
-      return { symbol, ratings: result.ratings, consensus: result.consensus };
-    }),
-});
+       return { symbol, ratings: result.ratings, consensus: result.consensus };
+     }),
+
+   /** Short interest (shares short, % float, short ratio) from yahoo-finance2 defaultKeyStatistics. */
+   shortInterest: publicProcedure
+     .input(z.object({ symbol: z.string().min(1) }))
+     .query(async ({ ctx, input }) => {
+       const symbol = input.symbol.toUpperCase();
+       const k = `yfinance:shortinterest:${symbol}`;
+       const entry = await ctx.cache.get<unknown>(k);
+       const value = entry.value as Record<string, unknown> | null;
+       return {
+         symbol,
+         sharesShort: value ? (value.sharesShort as number | null) : null,
+         sharesShortPriorMonth: value ? (value.sharesShortPriorMonth as number | null) : null,
+         sharesPercentSharesOut: value ? (value.sharesPercentSharesOut as number | null) : null,
+         shortRatio: value ? (value.shortRatio as number | null) : null,
+         shortPercentOfFloat: value ? (value.shortPercentOfFloat as number | null) : null,
+         dateShortInterest: value ? (value.dateShortInterest as string | null) : null,
+         floatShares: value ? (value.floatShares as number | null) : null,
+         sharesOutstanding: value ? (value.sharesOutstanding as number | null) : null,
+         stale: entry.isStale,
+         provenance: entry.provenance,
+       };
+     }),
+};
 
 // ─── EDGAR / SEC Filings Router (Slice 6 / M6) ────────────────────────────