26.112 — Initial Bilingual Codex & Exact Symbolic Engine (v0.1.0)

Established the complete geometor-durer repository for Albrecht Dürer’s Underweysung der Messung, mit dem Zirckel un[d] Richtscheyt, in Linien Ebnen unnd gantzen Corporen (Nuremberg, 1525; 2nd ed. 1538; Camerarius Latin ed. 1532):

• 4-Track Bilingual Digital Scriptorium Codex (docsrc/underweysung/) pairing an original GEOMETOR English translation directly from the 1525 Nuremberg Early New High German (English) with the diplomatic SLUB Dresden PPN 27778509X copy-text (German (1525)), structural digests (Summary), and mathematical commentary (Notes) across all Four Books.

• Exact Symbolic Engine (src/geometor/durer/) built on SymPy and geometor.model with zero floating-point coordinates:

  1. Book I 12-sector Archimedean spiral over $\mathbb{Q}(\sqrt{3})$ and two-view descriptive geometry of conic sections proving $w_k = \frac{\sqrt{2k(12-k)}}{3}$ ($w_{12-k} = w_k$).

  2. Book II direct comparison of Dürer’s single-aperture (“rusty compass”) pentagon ($Q = 1$, base angle $108.3661^\circ$, $+21.97'$ error) against Euclid’s $\mathbb{Q}(\phi)$ pentagon, plus Eisenstein cubic residual $P_7(\frac{3}{4}) = -\frac{1}{64}$ for the workshop heptagon and $\pi_{\text{Dürer}} = \frac{25}{8} = 3.125$.

  3. Book III Roman Antiqua capitals A, O, Q inside the $10 \times 10$ square and modular Gothic Textura minuscules i, n, m.

  4. Book IV planar fold-out nets for the Tetrahedron, Cube, Octahedron, Dodecahedron (double pentagonal rosette over $\mathbb{Q}(\sqrt{5}, \sin 36^\circ)$), Icosahedron, and Cuboctahedron, plus central perspective cube projection ($\operatorname{CR} = -1$) and Delian cube duplication ($c^3 = 2 g^3$).

• 11 Theme-Adaptive ``.euclid-graphic`` SVGs and 4 runnable scripts in demos/.