feat: sync upstream changes post-v1.7.0

[kaiserc]

Summary

Ports and adapts the 8 upstream commits from baairon/torlink merged after v1.7.0 (205cabb..8b1df42).

Changes Included

1. Deduplication & Tracker Merging: Merges all distinct tracker announce URLs (&tr=...) into surviving magnets upon deduplication and backfills missing metadata (numFiles, added).
2. Headless CLI Search Command: Adds torlnk search <query> [--category ...] emitting structured JSON, extended to support our fork's custom ebooks and audiobooks categories.
3. EZTV Text Search Fix: Adds 10-page recent index cache to resolve query keywords to show imdb_ids and fetch catalogues.
4. Feed Date Comparator Bugfix: Implements parseUnixSeconds returning undefined for invalid dates, preventing NaN sort comparator corruption.
5. OSC 52 Terminal Clipboard: Supports ANSI OSC 52 escape sequences (with tmux DCS passthrough), prioritizing remote SSH sessions to copy to local workstations.
6. Bounded LRU Search Cache: Caps cachedSearch at 100 entries with LRU eviction to prevent memory leaks in daemon / server modes.
7. Per-Machine WebRTC Opt-Out: Supports TORLINK_NO_WEBRTC=1 / KLINK_NO_WEBRTC=1 to stub WebRTC hooks at boot and avoid 100% idle CPU spinning on affected machines.
8. Prebuilt node-datachannel Binaries: Pins node-datachannel: "^0.33.1" and @node-datachannel/android-arm64: "0.33.0" via package overrides for zero-build npm 12+ compatibility.

Verification

• 58/58 test files passed (398 vitest tests).
• npm run typecheck passed with 0 errors.
• npm run build compiled production bundles cleanly.