chore(root): tidy repository root — relocate 9 docs to docs/ (Phase 1+2)

Move root-level documentation into the canonical docs/ tree per the RSR
root allowlist (rsr-template-repo/.machine_readable/root-allow.txt), taking
the tracked root from 43 to 34 entries. All moves are pure renames (R100);
REUSE compliance is preserved by the REUSE.toml **/*.{md,adoc,tex,bib} glob
annotations (reuse lint: 455/455 compliant, no REUSE.toml edit required).

Relocations:
  llm-warmup-{dev,user}.md               -> docs/onboarding/
  QUICKSTART-{USER,DEV,MAINTAINER}.adoc  -> docs/
  PROOF-NEEDS.md, TEST-NEEDS.md          -> docs/status/
  arcvix-10-level-query-safety.{tex,bib} -> docs/whitepapers/

Wire-first (functional references updated, non-licence):
  tests/e2e.sh                                  arcvix -> docs/whitepapers/
  verification/proofs/VERIFICATION-STANCE.adoc  PROOF-NEEDS -> docs/status/

Deferred to owner (Phase 3, documented in PR): container-cluster
consolidation (root Containerfile/stapeln.toml/selur-compose.toml couple to
each other and overlap container/compose.toml+manifest.toml), the build/+ci/
canonical relocation (~28 wiring edits across Justfile/.envrc/CI/tool-toml),
README.adoc.invariants.md home, and stale REUSE.toml explicit-path entries
(owner-only licence cleanup).

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

Author: hyperpolymath

QUICKSTART-DEV.adoc docs/QUICKSTART-DEV.adocQUICKSTART-DEV.adoc renamed to docs/QUICKSTART-DEV.adoc

@@ -73,7 +73,7 @@ echo ""
 # ── Category 3: VCL-total artefacts ───────────────────────────────────────
 echo "Category 3: VCL-total artefacts"
 
-check "arcvix paper (arXiv source) exists" "$([ -f arcvix-10-level-query-safety.tex ] && echo 0 || echo 1)"
+check "arcvix paper (arXiv source) exists" "$([ -f docs/whitepapers/arcvix-10-level-query-safety.tex ] && echo 0 || echo 1)"
 check "examples/ directory has content"    "$([ -d examples ] && ls examples/*.vcl 2>/dev/null | head -1 | grep -q . && echo 0 || echo 1)"
 check "features/ directory exists"        "$([ -d features ] && echo 0 || echo 1)"
 check "verification/ directory exists"    "$([ -d verification ] && echo 0 || echo 1)"