SyntaxFlow trade tables: glass weight, steel bar weight, timber volume and bricks per square metre

Four reference tables for glaziers, metalworkers, carpenters and builders, computed with the open formulas of the syntaxflow-formulas library (MIT), the same working used by the free calculators at syntaxflow.io: glass_weight_by_thickness.csv: float glass weight for 2 to 25 mm in kg/m², lb/ft² and kg/ft² (2.5 kg/m² per mm, 2500 kg/m³). steel_bar_weight_per_metre.csv: round steel bar and rebar weight in kg/m for 6 to 40 mm, exact (π/4·D²·7850/10⁶) and the site rule D²/162. timber_cubic_metres.csv: volume in m³ of 12 common timber sections in lengths of 2 to 6 m, pieces per m³, linear metres per m³ and board feet. bricks_per_m2.csv: bricks or blocks per m² of wall for six common face sizes with a 1 cm joint. CSV files in UTF-8 with a decimal point and the unit in each column name. README.md describes every column and formula. These are estimating values for quoting, ordering and handling, not a structural calculation.