fix: widget iOS 17 deployment target + register FloatingTabState

- Widget extension: 16.0 → 17.0 (containerBackground/widget API require 17)
- xcodegen re-run picks up FloatingTabState.swift (was on disk but
  not registered in project.pbxproj after previous xcodegen run)

KisaniCal/Components/FloatingTabState.swift

@@ -0,0 +1,52 @@
+import SwiftUI
+
+@MainActor
+final class FloatingTabState: ObservableObject {
+    @Published private(set) var isCollapsed = false
+    private var lastY: CGFloat = 0
+
+    func report(scrollY: CGFloat) {
+        let delta = scrollY - lastY
+        guard abs(delta) > 1.5 else { return }
+        let shouldCollapse = delta < 0  // content Y decreases → user scrolling down
+        lastY = scrollY
+        guard shouldCollapse != isCollapsed else { return }
+        withAnimation(KisaniSpring.snappy) {
+            isCollapsed = shouldCollapse
+        }
+    }
+
+    func resetOffset() {
+        lastY = 0
+    }
+}
+
+// MARK: — Scroll tracker
+
+private struct ScrollYKey: PreferenceKey {
+    static let defaultValue: CGFloat = 0
+    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) { value = nextValue() }
+}
+
+private struct TabBarScrollModifier: ViewModifier {
+    @EnvironmentObject private var tabState: FloatingTabState
+
+    func body(content: Content) -> some View {
+        content
+            .background(
+                GeometryReader { geo in
+                    Color.clear
+                        .preference(key: ScrollYKey.self, value: geo.frame(in: .global).minY)
+                }
+            )
+            .onPreferenceChange(ScrollYKey.self) { y in
+                tabState.report(scrollY: y)
+            }
+    }
+}
+
+extension View {
+    func trackScrollForTabBar() -> some View {
+        modifier(TabBarScrollModifier())
+    }
+}