The VFS image packer: turns one composed profile into the single gzip-compressed tar the browser worker inflates and mounts as its filesystem (experimental stance). Nothing is compiled from source — the image carries the repository's real build products, so a preview deployment debugs exactly what the served deployment ships.

The pack is a three-layer standard stack:

Roster — the composed profile's plugin rows (standard YAML parse under Include's dialect, !!js intact), plus the rows of every config tree the CLI declares in its package.json dsh.configTrees (agent presets), materialized as a Node-style dependency closure. External peer edges never bind the worker; workspace peers stay on the chain.
Publish view — each workspace package contributes the slice npm would publish (files through picomatch) minus the rule tables in src/rules.ts (no sources, no workspace dist/; external packages keep their trees minus the same exclude globs).
Reachability sweep — the runtime loader's own resolution walks from every workspace export face plus the worker assembly's seeds (IMAGE_ENTRY_SEEDS), lowering each reached module to the wrapper contract at pack time. Page assets (lib/client.js behind ./client exports) ship verbatim; an unresolvable request from our own code fails the pack, third-party ones are tolerated to fail loud at require time.

repository.ts owns the repo-shaped inputs (workspace scan of vendor/, packages/, apps/; profile composition through the real CLI dump path); pack.ts owns none of them, so the same library packs a different tree by being called differently. The CLI is dsh-pack-vfs-image --out <file> [--profile web]; apps/web's build:preview runs it after the preview shell build.

Model Experience

None, as this package runs at build time and writes an image file; nothing it produces reaches a model request on its own.

KV Cache effect

None; this package neither assembles nor sends a provider request.

Known Limitations and Deferred Work

The rule tables are judgement calls (rules.ts: exclude globs, page-asset patterns, entry seeds) pinned by tests/; a new asset class the worker must reach needs a table row, not a scanner change.
Vendored package sources (src/*.ts) no longer pack — nothing resolves them at runtime; a future in-worker source-inspection feature would need a dedicated include rule.
The packer assumes built lib/ artifacts are current: it never compiles, so a stale workspace build packs stale bytes. Run the repository build first.