Restructure three-pronged → knowledge-layers: collapse 11 files to 3, integrate into main architecture

- Rename 'three-pronged' folder to 'knowledge-layers' — prong metaphor
  was misleading (implied parallel tines), replaced with epistemic layers
  (deductive base, empirical middle, probabilistic oracle — vertical stack)
- Collapse 11 overlapping files into 3 coherent documents:
  - knowledge-layers/_index.org: core framework (two engines + one store,
    World Model formula, 0-14 layer table, provenance store design,
    conflict resolution, cold-start, stage mapping)
  - knowledge-layers/practical-implications.org: design-world-aware-of-
    physics, 10 powers, Schafmeister existence proof, epistemic transparency
  - knowledge-layers/neurological-empirical.org: neural networks in
    provenance framework (kept intact)
- Relocate wolfram/mathematica and Schafmeister docs to ideas/viability/
- Integrate into main architecture _index.org:
  - Gate: expanded from two vectors (ACL2+LLM) to three (deductive,
    provenance/empirical, LLM oracle)
  - Autodidactic loop: split into Track 1 (deductive hardening, fast)
    and Track 2 (empirical validation, slow, experimental-feedback-driven)
  - See also: added Knowledge Layers cross-reference
- Add all-lisp geometry engine note (ideas/lisp-geometry-engine.org) as
  concrete illustration of the empirical layer's effect on design work
- Rebuild site: 148 files, 0 errors

projects/passepartout/architecture/security.org

@@ -2,7 +2,7 @@
 :CREATED:  [2026-05-24 Sun]
 :ID:       1c95ce7d-a2db-506a-9608-df68f9ae211b
 :END:
-#+title: Lisp Machine Security — Unified Memory Threat Model
+#+title: Lisp Machine Security
 #+filetags: :passepartout:security:lisp-machine:pmp:isolation:
 
 On a bare metal [[id:13e6ae54-2d24-5aa0-b1cd-a7e8e749aa70][Lisp Machine]] with a unified Lisp image, the defense-in-depth provided by the OS kernel disappears. The gate stack and the code it protects share a single address space. An attacker who exploits a memory corruption in the browser renderer can modify the gate stack's permission tables, the policy engine's state, or the ACL2 prover's decision output. There is no kernel underneath to catch them.