swmm-anywhere

# swmm-anywhere **Synthesize a plausible SWMM drainage network from public data (OSM streets + DEM) when no real pipe-network data exists.** Use **ONLY** when the user explicitly does not have pipe shapefile / CAD / GIS data, or when establishing a baseline before real data arrives. **Do NOT use if `swmm-gis` or `swmm-network` can run on the user's actual data** — the synthesized network is an *inferred plausibility*, not measured infrastructure. For bbox-only inputs without real pipe data: this is the right skill. For inputs that include a `.shp`, `.csv`, or `network.json` of real pipes: route to `swmm-network` or `swmm-gis` instead. ## What this skill does Given a bounding box (and optional region name), this skill: 1. **Downloads public source data** via SWMManywhere: OpenStreetMap streets, a DEM tile (Planetary Computer by default), building footprints, river lines. 2. **Snapshots the raw inputs** under `runs/<date>/<id>/00_raw/` with a SHA-256 manifest that is **verified after capture** (the result lands in `synth_provenance.json` under `raw_snapshot_verified`), so the exact OSM/DEM inputs that produced this run are pinned and audited (OSM/DEM otherwise drift continuously upstream). 3. **Runs SWMManywhere's 24-step graph pipeline** to infer subcatchment polygons, manhole nodes, pipe topology, pipe diameters, and outfall locations. 4. **Writes a SWMM 5.2 `.inp`** under `runs/<date>/<id>/10_upstream/swmmanywhere/synth.inp` (the canonical upstream box, ADR-0004), post...