[isomorphisms]

Implements a first owner acceptance slice under FP envelope isomorphisms/flexible-pipes#239.

• Reuses bin/harvest_arxiv_images.grease and source.tsv/document.html. Separately extracts MathML alttext or TeX annotation, keeps raw formula and source paper URL/document SHA/MathML ordinal.
• Compiles and invokes the actual pinned SURFER PR Make IB hot paths compiler/backend optimization test targets #33 C formula parser plus native host renderer at 9113596d732f1c44db7d6e11ad8a12df3dc8d369; matches the 4 signed monomial/exponent tuples of x^4-x*y^3-z^4+z=0, never an image guess.
• Idriç typed policy allows only real affine W=1 signed target and records SURFER renderer candidacy.
• Host probe executes SURFER ray tracer on the parsed polynomial, with clipping/unit sphere and fixed 32×32 camera; this is not a finished, accepted still or movie.
• Always records media NOT_VERIFIED and Android interactive BLOCKED_NO_EXACT_RESTORE. No false image or link.
• Mutants: changed -z^4 sign, changed x^4 exponent, unsupported sin(x), conflicting MathML annotations, unrelated img alt text, wrong domain, missing chart, PDF without verified equation extraction. Old reading sources remain intact.

Not accepted yet: await exact-head GitHub CI and independent ai-ci receipt, finished image/movie reproducibility, SURFER Android editor/deep-link restoration, physical-device check. Do not merge based on this PR's owner tests.