Add peak KPS and CPS tracking

[Copilot]

Tracks the highest keys-per-second (KPS) and clicks-per-second (CPS) recorded within any 1-second sliding window during the current day, and surfaces these peaks in the stats UI on both macOS and Windows.

Data model

• Added peakKPS: Double / peakCPS: Double to DailyStats on both platforms, backward-compatible (decoded via decodeIfPresent / JSON optional)
• On import merge, takes the max of both sides rather than summing

Tracking logic (1-second sliding window)

Each key press / click enqueues a timestamp, purges entries older than 1 s, and updates the stored peak if the current window count exceeds it. Queues are cleared atomically with CurrentStats on day rollover.

macOS – dedicated peakRateLock protects the timestamp queues; currentStats.peakKPS/CPS is updated outside the lock, consistent with the rest of the codebase.

Windows – timestamp queues and peak update share _lock alongside CurrentStats, so the queue clear in SynchronizeCurrentDay is inherently atomic with the stats reset:

lock (_lock)
{
    _recentKeyTimestamps.Enqueue(now);
    while (_recentKeyTimestamps.Peek() <= cutoff) _recentKeyTimestamps.Dequeue();
    var kps = (double)_recentKeyTimestamps.Count;
    if (kps > CurrentStats.PeakKPS) CurrentStats.PeakKPS = kps;
}

UI

• macOS: new side-by-side peakKPSView / peakCPSView row appended to the stats stack in StatsPopoverViewController
• Windows: new card row (峰值 KPS / 峰值 CPS) added below the distance row in StatsPopupWindow.xaml, bound to PeakKPS / PeakCPS on StatsPopupViewModel
• Localization strings added for both en and zh-Hans

[Copilot]

Pull request overview

Adds per-day peak input-rate metrics (peak KPS/CPS over a 1-second sliding window) and displays them in the stats UI on macOS and Windows.

Changes:

• Extended the daily stats model with peakKPS / peakCPS (backward-compatible decoding).
• Implemented 1-second sliding-window peak tracking for keys and clicks.
• Surfaced peak KPS/CPS in the macOS popover and Windows stats popup UI.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
KeyStats/StatsManager.swift	Adds timestamp-window tracking and stores peak KPS/CPS in current daily stats.
KeyStats/StatsModels.swift	Extends DailyStats Codable model with peakKPS/peakCPS and defaults.
KeyStats/StatsPopoverViewController.swift	Displays peak KPS/CPS in the macOS stats popover.
KeyStats/en.lproj/Localizable.strings	Adds English localized labels for peak KPS/CPS.
KeyStats/zh-Hans.lproj/Localizable.strings	Adds Simplified Chinese localized labels for peak KPS/CPS.
KeyStats.Windows/KeyStats/Services/StatsManager.cs	Adds Windows-side peak tracking and clears windows on day rollover.
KeyStats.Windows/KeyStats/Models/DailyStats.cs	Adds JSON fields for peak KPS/CPS on Windows daily stats.
KeyStats.Windows/KeyStats/ViewModels/StatsPopupViewModel.cs	Exposes formatted PeakKPS/PeakCPS bindings for the popup UI.
KeyStats.Windows/KeyStats/Views/StatsPopupWindow.xaml	Adds two stat cards for Peak KPS/CPS.

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[Copilot]

PeakKPS/PeakCPS are now tracked and serialized on DailyStats, but the Windows import/normalize pipeline still drops them: NormalizeDailyStats(...) and MergeDailyStats(...) don’t copy/merge the new fields, so peaks will reset to 0 after load/import and won’t merge as described. Update normalization to carry forward sanitized PeakKPS/PeakCPS and update merge to use max(existing, incoming) for both fields.

[Copilot]

This peak-rate path allocates a new array on every keypress (filter + reassignment). Since it runs per input event, consider using a queue/deque (or an array with a moving start index + occasional compaction) to purge old timestamps in-place to reduce allocations/CPU; apply the same approach to the CPS tracker too.

[Copilot]

DailyStats gained new Codable fields (peakKPS/peakCPS) but the StatsModels test suite doesn’t currently cover their defaults/backward-compatible decoding. Add unit tests that (1) decode legacy JSON without these keys and assert both are 0, and (2) round-trip encode/decode preserves non-zero peaks.

Suggested change

	enum CodingKeys: String, CodingKey {
	case date
	case keyPresses
	case keyPressCounts
	case leftClicks
	case rightClicks
	case sideBackClicks
	case sideForwardClicks
	case mouseDistance
	case scrollDistance
	case appStats
	case peakKPS
	case peakCPS
	}
	init(from decoder: Decoder) throws {
	let container = try decoder.container(keyedBy: CodingKeys.self)
	self.date = try container.decode(Date.self, forKey: .date)
	self.keyPresses = try container.decode(Int.self, forKey: .keyPresses)
	self.keyPressCounts = try container.decode([String: Int].self, forKey: .keyPressCounts)
	self.leftClicks = try container.decode(Int.self, forKey: .leftClicks)
	self.rightClicks = try container.decode(Int.self, forKey: .rightClicks)
	self.sideBackClicks = try container.decode(Int.self, forKey: .sideBackClicks)
	self.sideForwardClicks = try container.decode(Int.self, forKey: .sideForwardClicks)
	self.mouseDistance = try container.decode(Double.self, forKey: .mouseDistance)
	self.scrollDistance = try container.decode(Double.self, forKey: .scrollDistance)
	self.appStats = try container.decode([String: AppStats].self, forKey: .appStats)
	self.peakKPS = try container.decodeIfPresent(Double.self, forKey: .peakKPS) ?? 0
	self.peakCPS = try container.decodeIfPresent(Double.self, forKey: .peakCPS) ?? 0
	}
	func encode(to encoder: Encoder) throws {
	var container = encoder.container(keyedBy: CodingKeys.self)
	try container.encode(date, forKey: .date)
	try container.encode(keyPresses, forKey: .keyPresses)
	try container.encode(keyPressCounts, forKey: .keyPressCounts)
	try container.encode(leftClicks, forKey: .leftClicks)
	try container.encode(rightClicks, forKey: .rightClicks)
	try container.encode(sideBackClicks, forKey: .sideBackClicks)
	try container.encode(sideForwardClicks, forKey: .sideForwardClicks)
	try container.encode(mouseDistance, forKey: .mouseDistance)
	try container.encode(scrollDistance, forKey: .scrollDistance)
	try container.encode(appStats, forKey: .appStats)
	try container.encode(peakKPS, forKey: .peakKPS)
	try container.encode(peakCPS, forKey: .peakCPS)
	}