nx_q14_format.nx

nx_q14_format.nx -- Q14 fixed-point i64 -> decimal ASCII string. Required by: - nx_gcode_emit (every X/Y/Z/E coordinate is a decimal text token) - audit dashboards + debug logs (Q14 coords must be human-readable) - operator-facing print summaries ("305.250mm × 305.250mm × ...") Two entry points: nx_int_to_decimal(value, buf, cap) basic signed i64 -> ASCII (no fractional part) nx_q14_to_decimal(value_q14, buf, cap, frac_digits) signed Q14 i64 -> "<int>.<frac>" with frac_digits decimals Behaviour: - Both write to caller-owned buf; do NOT NUL-terminate; return byte count written. - Negative inputs prefix "-". - frac_digits = 0 produces no decimal point. - Capacity check: returns -1 if buf would overflow. - Round-toward-zero on the fractional part (no rounding). Slicer + G-code use canonical Q14 representation throughout; rounding policy lives in the slicer, not the formatter. Q14 1 unit = 1/16384 = ~0.000061. Three fractional digits captures most operator-relevant precision (0.001 mm = 16.384 Q14 units; well above the formatter's truncation error). license_tier: ORIGINAL