docs(adr): commit the symbol foundation to the JVM/CDS model (pure)Verified

THIS IS THE DIRECTION. One symbol table baked into the image (static
section) + extended at runtime (arena), with compiled quotes referencing
the static record directly. No second copy, no per-door reconciliation.
It is HotSpot verbatim: static section ~= CDS shared archive + vmSymbols;
arena ~= the dynamic SymbolTable; lookup checks shared first, then dynamic.

- 0026: re-oriented from the arena-canonical *pragmatic shortcut* (codex's
  2026-06-28 near-term pick) to the *pure* foundation. Status -> direction
  committed. The pole-flip history is recorded so nobody re-litigates it.
  Key load-bearing detail spelled out: the static record can be canonical
  without re-breaking cave#120 because the self-host fixed point only
  requires stage2==stage3 (both funcl-built, both can populate + reference
  the static table); the elisp-built stage1 is allowed to differ. Phase 3
  (quote emission bakes a lea to the static record) is the heart; it needs
  a complete + deterministically-ordered static table, guarded by a new
  static-table-order witness.

- 0025: reciprocal note — the symbol table IS part of the CDS mapped image;
  going pure in 0026 and CDS here is one decision, sequence them together.

- 0023 banner + README index: cross-refs flipped from "arena, not baked"
  to the JVM/CDS one-table model.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>