1.4.1 (build 46): fix cambio de Chart Type roto por el cache de snapshots

El fetch del cache dependía del timeRange activo (monthsLimit = timeRange.months),
así que al reutilizarlo entre chart types/rangos (optimización del build 45) los
charts recibían historia truncada — Year vs Year o "All" con solo 12 meses, charts
vacíos o incompletos al cambiar de tipo.

Fix: el cache siempre guarda la historia completa (maxHistoryMonths) y el recorte
por rango se hace en memoria (el filtro por cutoffDate ya existía justo después).
Bonus: hiddenHistoryMonths ahora se calcula contra la ventana completa (teaser más
preciso).

Verificado en iPad Pro 13" simulador: Evolution 12M → All → Compare →
Period vs Period → Evolution, todos renderizan con datos.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015qUZrBusG82T37R7PeokqJ

PortfolioJournalUITests/PortfolioJournalUITests.swift

@@ -151,10 +151,42 @@ final class PortfolioJournalUITests: XCTestCase {
         }
         Thread.sleep(forTimeInterval: 3.0)
 
-        let shot = XCTAttachment(screenshot: capture.screenshot())
-        shot.name = "Charts_Redesign"
-        shot.lifetime = .keepAlways
-        add(shot)
+        func snap(_ name: String) {
+            let shot = XCTAttachment(screenshot: capture.screenshot())
+            shot.name = name
+            shot.lifetime = .keepAlways
+            add(shot)
+        }
+
+        snap("01_Evolution_default")
+
+        // Switch period to All (exercises the shared snapshot cache across ranges)
+        let allSegment = capture.buttons["All"].firstMatch
+        if allSegment.waitForExistence(timeout: 3) {
+            allSegment.tap()
+            Thread.sleep(forTimeInterval: 2.0)
+            snap("02_Evolution_All")
+        }
+
+        // Switch chart type to a free multi-control chart and back (cache reuse path)
+        let compareTile = capture.buttons["Compare"].firstMatch
+        if compareTile.waitForExistence(timeout: 3) {
+            compareTile.tap()
+            Thread.sleep(forTimeInterval: 2.0)
+            snap("03_Compare")
+        }
+        let periodTile = capture.buttons["Period vs Period"].firstMatch
+        if periodTile.waitForExistence(timeout: 3) {
+            periodTile.tap()
+            Thread.sleep(forTimeInterval: 2.0)
+            snap("04_PeriodVsPeriod")
+        }
+        let evolutionTile = capture.buttons["Evolution"].firstMatch
+        if evolutionTile.waitForExistence(timeout: 3) {
+            evolutionTile.tap()
+            Thread.sleep(forTimeInterval: 2.0)
+            snap("05_Evolution_back")
+        }
     }
 
     /// Captures full-screen screenshots of the main tabs with demo data for App Store