Build a Coastal Seawall Maintenance Work Order Synthesizer — implementation

## Build
Audit coastal seawall asset conditions using STAC digital elevation models and surge records. Construct structured maintenance work orders and localized inspection dossiers for harbor engineering teams.

## User
Harbor Asset Engineer

## Workflow
1. Ingest coastal defense structural manifests containing crest elevation, material type, and last inspection dates.
2. Query public STAC Item catalogs for post-surge high-resolution digital elevation models covering defense footprints.
3. Detect seawall crest elevation loss and shoreline toe scour exceeding maintenance tolerances.
4. Generate prioritized maintenance work orders with material estimates for municipal engineer review.

## Interface
FastAPI web dashboard with an interactive map of coastal defense assets, elevation profiles, and work order dispatch queues.

## Data
Utilize STAC API endpoints queryable via PySTAC, with sample GeoJSON DEM STAC items staged in local test fixtures.
Starter examples below are synthetic. They are not downloaded records.

## Source
[STAC specification](https://raw.githubusercontent.com/radiantearth/stac-spec/master/README.md)
Extracts STAC Item GeoJSON geometries, asset links, and spatiotemporal metadata according to the STAC 1.1.0 specification.

## Tools
langgraph, pystac, shapely.
Manages the multi-step cyclical state machine coordinating STAC asset fetching, elevation change analysis, and work order drafting.
Local or hosted LLM with strong technical drafting and tabular JSON output capabilities.

## 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
- Identifies elevation loss breaches along coastal barrier crest lines from STAC elevation assets.
- Constructs repair work order manifests specifying structural station markers and estimated concrete volume.
- Flags work orders for certified coastal engineering review prior to work ticket authorization.

## Starter Examples
```json
[
  {
    "input": {
      "_record_type": "simplified synthetic app record",
      "asset_id": "WALL-SECTOR-4B",
      "nominal_crest_m": 4.5,
      "survey_dem_elevation_m": 3.8,
      "length_affected_m": 60,
      "material": "reinforced_concrete"
    },
    "expected_output": {
      "asset_id": "WALL-SECTOR-4B",
      "maintenance_required": true,
      "crest_deficit_m": 0.7,
      "work_order": {
        "urgency": "high",
        "action": "crown_elevation_remediation",
        "est_grout_volume_m3": 42,
        "review_status": "pending_pe_signoff"
      }
    }
  },
  {
    "input": {
      "_record_type": "simplified synthetic app record",
      "asset_id": "WALL-SECTOR-12A",
      "nominal_crest_m": 5,
      "survey_dem_elevation_m": 5.1,
      "length_affected_m": 0,
      "material": "riprap"
    },
    "expected_output": {
      "asset_id": "WALL-SECTOR-12A",
      "maintenance_required": false,
      "crest_deficit_m": 0,
      "work_order": null
    }
  }
]
```

## Safety
Work orders are draft proposals for inspection and structural planning; no actual construction contracts or field repairs are initiated.
Use mock external writes. Require human review before any real deployment.