Optimize scan performance and add Smart Shredder

[Dezoff-max]

What changed

• replaced frame-driven scan progress rendering with event-driven progress and bounded newest-event buffering
• moved long read-only Disk Analysis and Duplicate Finder work to utility priority
• added a separate Smart Shredder sidebar destination with adaptive neo-glow styling
• added fail-closed descriptor-based overwrite and direct deletion for explicitly reviewed regular files
• added exact-phrase plus acknowledgement confirmation and clear SSD/APFS limitations
• added English/Russian localization, tests, and updated project documentation

Why

The scan progress UI continuously invalidated SwiftUI layout and sustained high CPU usage, which heated the Mac. The user also requested an isolated hacker-style tool for intentional irreversible file deletion.

Impact

The repeated Home Disk Analysis benchmark dropped from a 111–124% CPU baseline to 28.6% at startup, then 1.5% and idle-level samples while analysis remained active. Normal cleanup, duplicate removal, and application removal remain Trash-based. Smart Shredder is isolated from scans, scheduling, cleanup history, Trash, and restore.

Smart Shredder performs best-effort overwrite and direct unlink. It rejects directories, symlinks, hard links, package contents, protected roots, and files changed after review. The UI explicitly states that physical erasure cannot be guaranteed on SSD/APFS.

Validation

• swift test --package-path CleanMacCore — 47/47 passed
• focused SecureFileShredderTests — 4/4 passed
• Debug xcodebuild — passed
• ./script/build_and_run.sh --verify — build, ad-hoc signature, and launch passed
• EN/RU localization lint and 583-key parity — passed
• live EN/light and RU/dark UI review — passed without accepting destructive deletion
• git diff --check — passed

No real user file was deleted during verification.