check-onhand-coverage

name	check-onhand-coverage
description	Diff a project's BOM against the user's local on-hand inventory (the free-form list captured during onboarding). Reports which parts are already available, which need to be ordered, and which have plausible substitutes on hand.

Check On-Hand Coverage

Lightweight local inventory check — uses the inventory captured during onboard (free-form text or local file). For MCP-backed live inventory, use check-inventory instead.

Inputs

• Project slug → bom.json.
• inventory_source from config.json. If type is file, read it. If type is mcp, defer to check-inventory. If none, prompt the user to update onboarding.

Matching strategy

For each BOM line:

1. Exact match — same part number / module name.
2. Functional substitute — different part, same role (e.g. BOM wants BME280, user has BMP280; flag as "substitute, no humidity").
3. No match — must be sourced.

Substitutes are suggestions, not silent swaps. Flag every substitute so the user can decide whether the trade-off is acceptable.

Output

Write <projects_dir>/<slug>/coverage.md:

• Have (exact match) — qty available vs. qty needed.
• Have (substitute) — with trade-off note.
• Need to order — feeds directly into suggest-sourcing-options.

Print a one-line summary to the conversation: "X of Y parts on hand; Z need ordering."