Greptile Summary

This PR systematically addresses critical resource leaks, race conditions, and performance bottlenecks across the capture pipeline. The changes properly fix memory leaks by replacing orderOut(nil) with close() for windows, adding deinit methods with proper cleanup, tracking notification observers, and closing existing controllers before reassignment. The isCapturing race condition is fixed for OCR mode by posting completion notifications in all exit paths (success/cancel/error). Performance is dramatically improved by cropping images before applying CIFilter (50-100x faster for blur/pixelate on 4K), adding search debouncing (300ms), coalescing UserDefaults writes (0.5s), caching SCShareableContent (2s), and deduplicating canvas draws.

Key improvements:

• Fixed capture pipeline resource leaks (windows, mouse monitors, notification observers)
• Resolved OCR isCapturing race condition with completion notifications
• Optimized blur/pixelate annotations (crop-first approach)
• Added debouncing, caching, and write coalescing across the app
• Fixed force-unwrap crash, panel leaks, silent save failures
• Extracted shared utilities, enabled line rotation

One issue found:

• Timer mode has a remaining race condition when replacing an active timer - isCapturing resets to false before the new countdown starts, potentially allowing double-captures

Confidence Score: 4/5

• Safe to merge with one race condition issue to address in timer replacement flow
• The PR makes excellent improvements to resource management, performance, and code quality. All critical fixes are well-implemented except for one edge case: when replacing an active timer countdown, the isCapturing flag temporarily resets to false, allowing potential double-captures. This is a narrow race condition that only occurs when triggering a timer while another timer is counting down. The fix is straightforward and doesn't compromise the other improvements.
• Snapper/Capture/TimerCapture/TimerCaptureController.swift needs attention for the timer replacement race condition

Important Files Changed

Sequence Diagram

sequenceDiagram
    participant User
    participant CaptureCoordinator
    participant OCRController
    participant TimerController
    participant AppState

    Note over User,AppState: OCR Capture Flow (Race Condition Fixed)
    User->>CaptureCoordinator: Trigger OCR
    CaptureCoordinator->>AppState: isCapturing = true
    CaptureCoordinator->>OCRController: Post .startOCRCapture
    OCRController->>OCRController: Show area selector
    alt User completes selection
        OCRController->>OCRController: Process OCR
        OCRController->>CaptureCoordinator: Post .ocrCaptureDidFinish
    else User cancels
        OCRController->>CaptureCoordinator: Post .ocrCaptureDidFinish
    else Error occurs
        OCRController->>CaptureCoordinator: Post .ocrCaptureDidFinish
    end
    CaptureCoordinator->>AppState: isCapturing = false

    Note over User,AppState: Resource Leak Fixes
    User->>CaptureCoordinator: Trigger capture (area/window)
    CaptureCoordinator->>CaptureCoordinator: Close existing controller
    CaptureCoordinator->>CaptureCoordinator: Create new controller
    Note over CaptureCoordinator: Prevents controller overwrite leaks

_{Last reviewed commit: cd551e9}