Fix Yahoo Finance API: switch from v7 quote to v8 chart endpoint

The v7 /quote endpoint returns 401 Unauthorized as it now requires
cookie-based authentication. The v8 /chart endpoint works without auth.

- Switch to v8/finance/chart/{symbol} endpoint
- Fetch each symbol individually (chart API limitation)
- Update response parsing for chart JSON structure
- Calculate price change from regularMarketPrice - chartPreviousClose

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

IrisCompanion/iris/DataSources/StockDataSource.swift

@@ -80,106 +80,97 @@ final class StockDataSource {
             return Snapshot(data: cache.data, diagnostics: diagnostics)
         }
 
-        let symbolsParam = limitedSymbols.joined(separator: ",")
-        guard let encodedSymbols = symbolsParam.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
-              let url = URL(string: "https://query1.finance.yahoo.com/v7/finance/quote?symbols=\(encodedSymbols)") else {
-            diagnostics["error"] = "invalid_url"
-            throw StockError.networkFailed(message: "Invalid URL", diagnostics: diagnostics)
-        }
+        // Fetch each symbol using v8 chart API (supports one symbol per request)
+        var quotes: [StockQuote] = []
+        var fetchErrors: [String] = []
 
-        var request = URLRequest(url: url)
-        request.setValue("Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X)", forHTTPHeaderField: "User-Agent")
-        request.setValue("application/json", forHTTPHeaderField: "Accept")
-
-        let data: Data
-        let response: URLResponse
+        for symbol in limitedSymbols {
             do {
-            (data, response) = try await URLSession.shared.data(for: request)
+                if let quote = try await fetchQuote(symbol: symbol) {
+                    quotes.append(quote)
+                }
             } catch {
-            diagnostics["error"] = "network_error"
-            diagnostics["error_message"] = String(describing: error)
-            if let cached = cache {
-                diagnostics["source"] = "cache_fallback"
-                return Snapshot(data: cached.data, diagnostics: diagnostics)
+                fetchErrors.append("\(symbol): \(error.localizedDescription)")
             }
-            throw StockError.networkFailed(message: String(describing: error), diagnostics: diagnostics)
-        }
-
-        if let httpResponse = response as? HTTPURLResponse {
-            diagnostics["http_status"] = String(httpResponse.statusCode)
-            if httpResponse.statusCode == 403 {
-                diagnostics["error"] = "rate_limited"
-                if let cached = cache {
-                    diagnostics["source"] = "cache_fallback"
-                    return Snapshot(data: cached.data, diagnostics: diagnostics)
-                }
-                throw StockError.rateLimited(diagnostics: diagnostics)
-            }
-            guard (200..<300).contains(httpResponse.statusCode) else {
-                diagnostics["error"] = "http_error"
-                if let cached = cache {
-                    diagnostics["source"] = "cache_fallback"
-                    return Snapshot(data: cached.data, diagnostics: diagnostics)
-                }
-                throw StockError.networkFailed(message: "HTTP \(httpResponse.statusCode)", diagnostics: diagnostics)
-            }
-        }
-
-        let yahooResponse: YahooQuoteResponse
-        do {
-            yahooResponse = try JSONDecoder().decode(YahooQuoteResponse.self, from: data)
-        } catch {
-            diagnostics["error"] = "json_decode_error"
-            diagnostics["error_message"] = String(describing: error)
-            if let cached = cache {
-                diagnostics["source"] = "cache_fallback"
-                return Snapshot(data: cached.data, diagnostics: diagnostics)
-            }
-            throw StockError.invalidResponse(diagnostics: diagnostics)
-        }
-
-        let quotes: [StockQuote] = (yahooResponse.quoteResponse.result ?? []).compactMap { quote in
-            guard let price = quote.regularMarketPrice else { return nil }
-            return StockQuote(
-                symbol: quote.symbol,
-                shortName: quote.shortName ?? quote.symbol,
-                price: price,
-                change: quote.regularMarketChange ?? 0,
-                changePercent: quote.regularMarketChangePercent ?? 0,
-                marketState: quote.marketState ?? "CLOSED"
-            )
         }
 
         diagnostics["source"] = "network"
         diagnostics["quotes_returned"] = String(quotes.count)
+        if !fetchErrors.isEmpty {
+            diagnostics["fetch_errors"] = fetchErrors.joined(separator: "; ")
+        }
 
         let stockData = StockData(quotes: quotes)
         cache = (timestamp: now, data: stockData)
 
         return Snapshot(data: stockData, diagnostics: diagnostics)
     }
-}
 
-// MARK: - Yahoo Finance API Response Models
-
-private struct YahooQuoteResponse: Codable {
-    let quoteResponse: QuoteResponse
-
-    struct QuoteResponse: Codable {
-        let result: [Quote]?
-        let error: QuoteError?
+    private func fetchQuote(symbol: String) async throws -> StockQuote? {
+        guard let encodedSymbol = symbol.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
+              let url = URL(string: "https://query1.finance.yahoo.com/v8/finance/chart/\(encodedSymbol)?interval=1d&range=1d") else {
+            return nil
         }
 
-    struct Quote: Codable {
-        let symbol: String
+        var request = URLRequest(url: url)
+        request.setValue("Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X)", forHTTPHeaderField: "User-Agent")
+        request.setValue("application/json", forHTTPHeaderField: "Accept")
+
+        let (data, response) = try await URLSession.shared.data(for: request)
+
+        if let httpResponse = response as? HTTPURLResponse {
+            guard (200..<300).contains(httpResponse.statusCode) else {
+                throw StockError.networkFailed(message: "HTTP \(httpResponse.statusCode)", diagnostics: [:])
+            }
+        }
+
+        let chartResponse = try JSONDecoder().decode(YahooChartResponse.self, from: data)
+
+        guard let result = chartResponse.chart.result?.first,
+              let meta = result.meta,
+              let price = meta.regularMarketPrice else {
+            return nil
+        }
+
+        let previousClose = meta.chartPreviousClose ?? meta.previousClose ?? price
+        let change = price - previousClose
+        let changePercent = previousClose > 0 ? (change / previousClose) * 100 : 0
+
+        return StockQuote(
+            symbol: meta.symbol ?? symbol,
+            shortName: meta.shortName ?? meta.symbol ?? symbol,
+            price: price,
+            change: change,
+            changePercent: changePercent,
+            marketState: meta.marketState ?? "CLOSED"
+        )
+    }
+}
+
+// MARK: - Yahoo Finance v8 Chart API Response Models
+
+private struct YahooChartResponse: Codable {
+    let chart: Chart
+
+    struct Chart: Codable {
+        let result: [ChartResult]?
+        let error: ChartError?
+    }
+
+    struct ChartResult: Codable {
+        let meta: ChartMeta?
+    }
+
+    struct ChartMeta: Codable {
+        let symbol: String?
         let shortName: String?
         let regularMarketPrice: Double?
-        let regularMarketChange: Double?
-        let regularMarketChangePercent: Double?
+        let chartPreviousClose: Double?
+        let previousClose: Double?
         let marketState: String?
     }
 
-    struct QuoteError: Codable {
+    struct ChartError: Codable {
         let code: String?
         let description: String?
     }