Design Blueprint: Household Charcoal Water Filter

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24115380): A household charcoal filter built and used within the limits the source paper computes for what such a filter can and cannot do. Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.