version

name	version
scope	co-deck
version	1.3.0
description	Manages version snapshots of lecture files. Auto-backs up files before edits and restores prior versions on demand. Must be called before any file modification by any agent. Responds to "go back to previous version", "show version list". Cross-cutting — applies to all workflow stages.
status	active
owner	version
last_reviewed	"2026-06-20T00:00:00.000Z"
prerequisites	none

Context

Tracks every file change and manages snapshots so any prior state can be restored at any time. This is a cross-cutting skill — it must be called before any file modification by any other agent, without exception. PM Agent enforces this order automatically.

When to Use

• Before another agent edits a file (Storyline, Design, Build, Measure, Export, etc.)
• User says "go back to previous version"
• User says "show version list"
• PM Agent is about to perform a destructive (overwrite) change

---

Execution Steps

Step 1: Create Snapshot (before any edit)

Always create a snapshot before editing a file. --workspace is required.

# Single file
bun scripts/co-deck/snapshot.ts slide_deck.md \
  --workspace presentations/<project> \
  --desc "shrink chapter 3 slide count" \
  --agent content

# Multiple files
bun scripts/co-deck/snapshot.ts slide_deck.md storyline.md \
  --workspace presentations/<project> \
  --desc "full chapter restructure" \
  --agent content

# HTML file (large — snapshot only when layout changes)
bun scripts/co-deck/snapshot.ts lecture_v1.html \
  --workspace presentations/<project> \
  --desc "backup before image swap" \
  --agent build

# Diagram assets (shared pool)
bun scripts/co-deck/snapshot.ts ../assets/diagrams/ \
  --workspace presentations/<project> \
  --desc "backup before diagram regeneration" \
  --agent build

File paths are relative to --workspace.

--agent value rules:

Agent	--agent value
PM Agent	pm
Research Agent	research
Storyline Agent	storyline
Design Agent	design
Build Agent	build
Measure Agent	measure
Export Agent	export
Manual backup	manual

---

Step 2: List Versions

bun scripts/co-deck/snapshot.ts --workspace presentations/<project> --list

Example output:

──────────────────────────────────────────────────────────
  Stored versions (5, newest first)
──────────────────────────────────────────────────────────
  [ 1] 2026-06-17_16-00_build_image-swap-backup
        Files: 3 / Size: 2.4MB
  [ 2] 2026-06-17_14-30_content_chapter-adjust
        Files: 2 / Size: 45KB

---

Step 3: Restore a Version

# Full version ID
bun scripts/co-deck/snapshot.ts \
  --workspace presentations/<project> \
  --restore 2026-06-17_14-30_content_chapter-adjust

# Partial version ID (if uniquely matched)
bun scripts/co-deck/snapshot.ts \
  --workspace presentations/<project> \
  --restore 2026-06-17_14-30

Restore automatically backs up the current file before restoring. If you regret the restore, run --restore again on the new backup.

---

Output Format

Snapshots are stored under presentations/<project>/_versions/:

presentations/<project>/
└── _versions/
    └── 2026-06-17_14-30_content_chapter-adjust/
        ├── slide_deck.md
        └── storyline.md

Each snapshot auto-appends an entry to presentations/<project>/VERSIONS.md with date, agent, description, file sizes, and restore command.

Caveats:

• Add _versions/ to .gitignore — large folders make Git inefficient
• HTML files are 100KB–several MB; snapshot only on layout changes
• presentations/assets/fonts/ does not need snapshots — re-downloadable any time via download-font.ts
• Snapshot layout_spec.json + pdf_layout_spec.md together when HTML layout changes (they become invalid if HTML changes)

Related Skills

• html-build — must call this skill before editing the HTML file
• storyline — must call this skill before editing slide_deck.md or storyline.md
• measure — must call this skill before re-running measurement (snapshots layout_spec.json)