refactor(root): move root artefacts to their canonical locations (#76)

refactor(root): move root artefacts to their canonical locations

Applies the estate root-shape rollout: files that are not root-level by
necessity move to where their tooling and the estate canon expect them,
and
every reference to them is updated in the same change.

  * .envrc
  * .github/hooks/validate-a2ml.sh
      (from .githooks/validate-a2ml.sh)
      ->   .github/hooks/validate-a2ml.sh
  * .github/hooks/validate-k9.sh
      (from .githooks/validate-k9.sh)
      ->   .github/hooks/validate-k9.sh
  * .github/workflows/dogfood-gate.yml
  * CONTRIBUTING.adoc
      (deleted)
  * build/guix.scm
      (from guix.scm)
      ->   build/guix.scm
  * docs/RSR_OUTLINE.adoc

Verified with `git apply --check` against current main before
committing; no
behaviour change intended, the Justfile entry points keep working.

Author: hyperpolymath

.envrc

@@ -7,8 +7,8 @@ if has asdf; then
   use asdf
 fi
 
-# Load Guix shell if guix.scm exists
-if has guix && [ -f guix.scm ]; then
+# Load Guix shell if build/guix.scm exists
+if has guix && [ -f build/guix.scm ]; then
   use guix
 fi
 

.githooks/validate-a2ml.sh .github/hooks/validate-a2ml.sh.githooks/validate-a2ml.sh renamed to .github/hooks/validate-a2ml.sh

@@ -38,7 +38,7 @@ jobs:
 
       - name: Validate A2ML manifests
         if: steps.detect.outputs.count > 0
-        run: bash .githooks/validate-a2ml.sh
+        run: bash .github/hooks/validate-a2ml.sh
       - name: Write summary
         run: |
           A2ML_COUNT="${{ steps.detect.outputs.count }}"
@@ -82,7 +82,7 @@ jobs:
 
       - name: Validate K9 contracts
         if: steps.detect.outputs.k9_count > 0
-        run: bash .githooks/validate-k9.sh
+        run: bash .github/hooks/validate-k9.sh
       - name: Write summary
         run: |
           K9_COUNT="${{ steps.detect.outputs.k9_count }}"

.githooks/validate-k9.sh .github/hooks/validate-k9.sh.githooks/validate-k9.sh renamed to .github/hooks/validate-k9.sh

@@ -35,7 +35,7 @@ git init
 just init
 
 # Enter development environment
-guix shell -D -f guix.scm
+guix shell -D -f build/guix.scm
 
 # Validate compliance
 just validate-rsr