Ground Model: skid-to-roll dynamics on slopes and regional surfaces

[d-sorgcodexagent]

Parent: #4267

Implement slip-to-roll transition, static/kinetic friction, rolling resistance, gravity on slope, changing surface normals/regions, path integration, stop/out-of-bounds/step-limit states, and low-speed analytic fixtures. Reuse only dimensionally valid putting primitives and document applicability.

[linear]

D-7651

[d-sorgcodexagent]

Published the independently reviewed static-plane Python slice as draft PR #4304.

• Current carrier: aaff1bc
• Immutable implementation evidence: dcc8013
• Exact parent: 920c46d
• Local gates: 115 ground tests on CPython 3.11 and real 3.10; pinned MyPy/Ruff; manifest, docs, assertion, structural, file-size, and diff checks.
• Independent adversarial review closed all six pre-publication blockers.

This does not close #4271. Changing normals and regional surfaces remain unimplemented, and protected CI/review/dependency integration are still required.

[d-sorgcodexagent]

PR #4304 advanced normally to corrected carrier 482cdf272b04c78b50da91a6d2ddd4d15e063c7b on unchanged base feat/4270-ground-impact-bounce (920c46dee688815691e251777142126bf1489b1a).

Hosted quality-gate run 31354071845 found ten deterministic MyPy 1.13 no-any-return errors because the changed-file lane skips imported implementations. Immutable implementation f475ae85feea1b2c628f756699b2aba6ea9334fb only adds explicit float/bool normalization at already validated NumPy-backed scalar boundaries; no physics, numerical value/order, schema, output, API, scope, or base changed.

Local requalification is green: 115/115 ground tests on CPython 3.11.9 and real 3.10.20, pinned MyPy across 25 modules, pinned Ruff, 8/8 manifest contracts, and docs governance. The failed run was not retried; the normal push triggered fresh protected checks. Issue #4271 remains open for regional/changing-normal surfaces and remaining product/release criteria.

[d-sorgcodexagent]

Published the next bounded regional-surface continuation as draft PR #4332 from exact #4304 head ee77b059bd83f7dafac7e0d411665231cdb7435c.

Delivered: deterministic finite coplanar material overlays, unique overlap precedence, exact quadratic boundary splitting, base-edge priority, continuous no-impulse state, strict surface_transition event parity, an internal from/to region/surface ledger, active-material force/path/work accounting, and typed transition caps. Canonical specs, campaign manifest, and all handoffs are updated in the same commit.

Local evidence is green: 121 ground tests independently repeated, focused 38 tests, React 106 files/662 tests, focused TypeScript contract tests, type-check, zero-warning ESLint, production build, Ruff, pinned MyPy, manifest/docs/assertion/diff/size governance.

Issue #4271 remains open. This PR does not implement changing normals/heights/surface velocities, versioned regional wire requests/results, advanced terrain calibration/physics, regional UI, compiled-runtime regional physics, UpstreamDrift parity, or protected dependency release.

[d-sorgcodexagent]

Published draft PR #4335 from exact commit d382ca9928628a16fec7ddd4fa1b1cc144b4c490 as the direct child of #4332. It adds strict Python/TypeScript regional-plan request/result contracts, shared canonical digests/fixtures, bounded validation, and the Python resolver binding. All local contract, full React, static, build, documentation, manifest, policy, and secret-scan gates are green. This does not complete #4271: matched UI, non-coplanar/dynamic surfaces, broader runtime parity, protected CI/review, and dependency landing remain open.

[d-sorgcodexagent]

Ground-stack ancestry repair checkpoint: draft PR #4304 is now published at exact head 0ea6740965068542e9d8c7449e06ec07d88969e0, preserving live skid/roll child 52d9a6a978d8e6b8b19ef92f02f265c9058b00ad first and exact current impact/bounce parent cf6e72bad98e5f36f782254942e6895b8b71e670 second. The PR base remains feat/4270-ground-impact-bounce; no rebase, retarget, force-push, or parent rewrite was used.

Independent review verified that all 24 current-parent delta paths match the live base byte-for-byte, all ground implementation paths remain child-identical, and the one skid/roll test edit is formatting-only/AST-identical. Evidence includes 115 ground tests, 8 manifest tests, pinned Ruff/MyPy, docs/manifest/diff gates, and mandatory 400-line module, 50-line function, and four-parameter limits. SPEC is synchronized at 1.14.26.

Fresh protected current-head CI and review are required, and #4332+ descendants must still be propagated normally. This does not close #4271/#4267; regional execution/provenance binding, non-coplanar/dynamic surfaces, calibration, compiled parity, consumer integration, and release remain open.