v0.5.0

Added

• Quantity arithmetic at @pascal-app/lingo/calc. Closed calculator over
  already-parsed values — no variables, functions, or dimensional algebra.
  calc('7m*2') is 14 million (glued m at an operator boundary, with
  SCALE_ASSUMED); calc('9min x 4') is 36 min or 0.6 h;
  calc('half of 56kg+1700g') is 28.85 kg. Results format as words
  ("14 million"), grouped ("14,000,000"), scientific ("14e6"), or
  compact ("14m"). expression is two-way infix (7e6 × 2); latex is
  display-only. Inject calc into completions() and quantityField() so
  mixed fields keep range-first dashes (5-10 kg stays a range; =2+3 kg
  evaluates).
• Issue codes AFFINE_DELTA_ASSUMED, EXPRESSION_KIND_MISMATCH,
  SCALAR_EXPECTED, DIVISION_BY_ZERO, SCALE_ASSUMED.

Changed

• 2+3 kg is no longer a silent 2–3 kg range (CJK adjacent-range false
  positive). It fails with TRAILING_INPUT; use calc('2+3 kg') for 5 kg.
  Genuine CJK juxtaposition (七八天) is unchanged. Not an English corpus
  row; recorded as an interpretation change in D73.
• Additive affine compounds (20°C + 5°C) still delta-convert, and now warn
  AFFINE_DELTA_ASSUMED.

Fixed

• quantityField({ calc }) accepts division (10 kg / 2, 10kg/2) without
  treating glued fractions (5/10 kg) as arithmetic.
• Compact/scientific/latex calc output keeps tight unit symbols (25°C,
  10%, $5) instead of dropping them.
• calc('1e999') reports NONFINITE instead of masking it as NO_VALUE.
• SCALAR_EXPECTED copy no longer claims 10 / 2 kg is two quantities.
• Cross-currency arithmetic in calc() reports RATE_REQUIRED instead of
  treating every currency factor as 1, or masking the conversion throw as
  NONFINITE.
• Percent arithmetic normalizes basis points and per-mille values through the
  percent base unit (100 bps of 50 kg is 0.5 kg, not 50 kg).
• Same-kind affine ratios use canonical base values, so equivalent Celsius and
  Fahrenheit expressions agree and absolute zero alone is a zero divisor.
• Unclosed groups no longer evaluate successfully, unary group spans include
  their sign, and serialized calc issue spans include their source text.
• quantityField({ calc }) recognizes the calculator's word forms including
  over, multiplied by, bare half, spelled percent, and basis points.