chore: import upstream snapshot with attribution

Sources/CodexBar/AdaptiveRefreshPolicy.swift

@@ -0,0 +1,35 @@
+import AdaptiveRefreshCore
+import Foundation
+
+/// Decides how long to wait before the next automatic usage refresh.
+/// Pure by construction: every signal arrives via `Input`, so the same
+/// input always yields the same `Decision` with no clock or system reads.
+struct AdaptiveRefreshPolicy: Sendable {
+    struct Input: Sendable, Equatable {
+        let now: Date
+        let lastMenuOpenAt: Date?
+        let lowPowerModeEnabled: Bool
+        let thermalState: ProcessInfo.ThermalState
+    }
+
+    typealias Reason = AdaptiveRefreshPolicyCore.Reason
+    typealias Decision = AdaptiveRefreshPolicyCore.Decision
+
+    /// Representative cadence for consumers that need a single interval but cannot reach live
+    /// signals (`ProviderRegistry` builds provider specs before a `UsageStore` exists). Matches
+    /// `warmDelay`: the steady-state cadence while the user is active, which is when
+    /// interval-derived heuristics such as the persistent-CLI-session idle window matter most.
+    static let nominalIntervalForHeuristics = AdaptiveRefreshPolicyCore.nominalIntervalForHeuristics
+
+    func nextDelay(for input: Input) -> Decision {
+        AdaptiveRefreshPolicyCore().nextDelay(for: AdaptiveRefreshPolicyCore.Input(
+            now: input.now,
+            lastMenuOpenAt: input.lastMenuOpenAt,
+            lowPowerModeEnabled: input.lowPowerModeEnabled,
+            thermalPressure: Self.isConstrained(input.thermalState) ? .constrained : .nominal))
+    }
+
+    private static func isConstrained(_ state: ProcessInfo.ThermalState) -> Bool {
+        state == .serious || state == .critical
+    }
+}