Add tooltip coach mark tutorial for new users

- TutorialManager: tracks 4 steps (NLP, Calendar, Matrix, Workout)
  persisted via AppStorage; shown once then never again
- TutorialView: fullscreen overlay with even-odd spotlight cutout,
  animated accent border, ultraThinMaterial callout card, pill progress
  dots, Next/Get started button, and Skip
- TutorialFrameKey: PreferenceKey collects CGRect for each anchor index;
  .tutorialAnchor() modifier wired to FAB (step 0) and all 4 tab buttons
- Callout auto-positions above or below the spotlight based on screen half
- ContentView collects frames via onPreferenceChange and layers the overlay

Co-Authored-By: Kutesir <tqwyy79vzn@privaterelay.appleid.com>

KisaniCal/Managers/TutorialManager.swift

@@ -0,0 +1,48 @@
+import SwiftUI
+
+struct TutorialStep {
+    let title: String
+    let body: String
+    let icon: String
+    let anchorIndex: Int
+}
+
+@MainActor
+final class TutorialManager: ObservableObject {
+    static let shared = TutorialManager()
+
+    @AppStorage("kisani.tutorial.done.v1") private(set) var completed: Bool = false
+    @Published var step: Int = 0
+
+    let steps: [TutorialStep] = [
+        .init(title: "Add Tasks with NLP",
+              body: "Type naturally — \"dentist tomorrow 3pm\" or \"mum's birthday on 8th June every year\" — Kisani parses the date, time, and recurrence for you.",
+              icon: "sparkles",
+              anchorIndex: 0),
+        .init(title: "Calendar",
+              body: "See tasks and iPhone calendar events side-by-side, day by day. Nothing falls through the cracks.",
+              icon: "calendar",
+              anchorIndex: 1),
+        .init(title: "Eisenhower Matrix",
+              body: "Sort tasks into Urgent, Schedule, Delegate, or Eliminate. Focus on what actually moves the needle.",
+              icon: "square.grid.2x2",
+              anchorIndex: 2),
+        .init(title: "Workout Tracker",
+              body: "Build programs, log sets, and keep your streak alive. Your gym routine lives right here.",
+              icon: "dumbbell",
+              anchorIndex: 3),
+    ]
+
+    var isActive: Bool { !completed }
+    var current: TutorialStep { steps[min(step, steps.count - 1)] }
+    var isLast: Bool { step == steps.count - 1 }
+
+    func advance() {
+        if isLast { withAnimation(KisaniSpring.exit) { completed = true } }
+        else { withAnimation(KisaniSpring.entrance) { step += 1 } }
+    }
+
+    func skip() {
+        withAnimation(KisaniSpring.exit) { completed = true }
+    }
+}