📚 Smart Archiving

• Version tracking: automatically detects every modification to an article, saving v1, v2, v3…
• Content diff: sip --diff 123 v1 v3 clearly shows the changes
• Snapshot archiving: timestamped snapshots of a whole feed, permanently preserving the complete state at a moment in time
• Reading progress memory: exit the TUI and come back, resume from where you left off
• Feed identity & health: sip --feed-info <id> shows a feed's name/type/author/website/last update/latest article/status; -l auto-marks "⚠ not updated for a long time" and "✗ failed N times"
• Content quality marking: -l <id> marks articles that are summary-only ([summary]) or have no body ([no body]); JSON output carries a quality field (full / short / empty)