Table formulas !24

• Calc: integers, 12-digit decimal floats, operators with Calc precedence, v-functions, sqrt/exp/ln/log10/trig, float/fix/sci/eng display; 475 expressions match calc-eval.
• org-table-recalculate port: column, field, row and range formulas, @I/@-1/@</@>/$#/@#, $N..$M, format flags and printf; matches Emacs on 20 tables at every row and on corpus #+TBLFM lines.
• Outside the native domain the command returns .external(.emacsTable); the app recalculates in emacs --batch and splices the table back if unchanged. Lisp formulas ask first (trusted.json).

Plan: docs/plans/2026-10-05-table-formulas.md