Build an IFC 5D Construction Procurement Bill of Quantities Generator — implementation

## Build
Extract material schedules and dimensional takeoffs from Industry Foundation Classes models using ifc5d and ifccsv conventions. Generate structured bills of quantities aligned with procurement packages and flag unassigned unit rates.

## User
Procurement Estimator

## Workflow
1. Ingest structural and architectural IFC models and extract quantity takeoffs via ifc5d rules.
2. Map element schedule quantities to procurement line items using ifccsv classification keys.
3. Detect elements missing cost codes, unit dimensions, or material supplier rate bindings.
4. Publish formatted procurement bill of quantities with flags for cost estimation review.

## Interface
Browser dashboard showing procurement items table, missing rate warnings, and CSV export action.

## Data
Generate synthetic IFC JSON element snapshots representing concrete slabs and structural steel beams with quantity attributes.
Starter examples below are synthetic. They are not downloaded records.

## Source
[IfcOpenShell](https://raw.githubusercontent.com/IfcOpenShell/IfcOpenShell/v0.8.0/README.md)
Applies ifc5d and ifccsv tool utilities from IfcOpenShell contents table for reporting cost and schedule quantities.

## Tools
pydantic-ai, fastapi, uvicorn.
Pydantic AI enforces type-safe schemas across parsed IFC elements and procurement bill item structures.
Requires an instruction-following model with JSON mode accessed through standard API.

## Deliverables
Submit runnable source, pinned dependencies, setup commands, a working interface, example outputs, and a recorded end-to-end demo. Include tests and an action log.

## Acceptance
- Bill of quantities calculates total cost per line item when unit price is provided.
- Missing cost codes or unit prices are flagged as pending human input without failure.
- Output JSON conforms to standardized line-item schema with unit and total quantities.

## Starter Examples
```json
[
  {
    "input": {
      "project_id": "PRJ-901",
      "elements": [
        {
          "id": "BEAM-01",
          "type": "IfcBeam",
          "material": "Structural Steel S355",
          "quantity": 12.5,
          "unit": "m",
          "unit_cost": 45
        },
        {
          "id": "SLAB-01",
          "type": "IfcSlab",
          "material": "Reinforced Concrete C30",
          "quantity": 80,
          "unit": "m2",
          "unit_cost": 65
        }
      ]
    },
    "expected_output": {
      "project_id": "PRJ-901",
      "line_items_count": 2,
      "total_estimated_cost": 5762.5,
      "unassigned_rates_count": 0,
      "review_status": "READY_FOR_PURCHASE"
    }
  },
  {
    "input": {
      "project_id": "PRJ-902",
      "elements": [
        {
          "id": "COL-04",
          "type": "IfcColumn",
          "material": "Cast-in-place Concrete",
          "quantity": 4,
          "unit": "m3",
          "unit_cost": null
        }
      ]
    },
    "expected_output": {
      "project_id": "PRJ-902",
      "line_items_count": 1,
      "total_estimated_cost": 0,
      "unassigned_rates_count": 1,
      "review_status": "ACTION_REQUIRED"
    }
  }
]
```

## Safety
Estimates are strictly simulated drafts for procurement planning and require estimator sign-off before contract award.
Use mock external writes. Require human review before any real deployment.