fix(ci): propose spec to the canonical registry path, not a flat orphan path

The propose-spec step wrote to specs/${SPEC_KEY}/${SPEC_KEY}-tech-spec.md.
The canonical path in the registry's MANIFEST.json includes the domain
directory: specs/dve-core/sirus/sirus-tech-spec.md. The flat
specs/sirus/ directory does not exist in the registry, so mkdir -p created
it and every proposal landed as a new orphan file instead of updating the
canonical spec.

Effect: the registry's canonical sirus spec has not been updated from this
repository since the 2026-06-16 consolidation pass. Every consuming repo's
fetch-specs CI gate has been served that stale copy.

Changes:
- Add SPEC_DOMAIN and build TARGET from it.
- Replace mkdir -p of the target directory with an existence check that fails
  the job loudly if the canonical path is absent, rather than silently
  creating a path the registry does not track.

The same defect is present in the other repos that call propose-spec; each is
fixed in its own PR.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01U8mxZVHUrAa5NpUJruLzQm

Author: SparxstarDevelopment

.github/workflows/governance.yml

@@ -126,18 +126,27 @@ jobs:
         env:
           GH_TOKEN: ${{ steps.token.outputs.token }}
           SPEC_KEY: "sirus"
+          # Canonical registry path from MANIFEST.json INCLUDES the domain
+          # directory. A flat specs/<key>/ target creates an orphan file
+          # instead of updating the canonical spec.
+          SPEC_DOMAIN: "dve-core"
         run: |
           REGISTRY="Starisian-Technologies/sparxstar-product-specification-registry"
           BRANCH="propose/${SPEC_KEY}-$(date +%Y%m%d-%H%M%S)"
-          TARGET="specs/${SPEC_KEY}/${SPEC_KEY}-tech-spec.md"
+          TARGET="specs/${SPEC_DOMAIN}/${SPEC_KEY}/${SPEC_KEY}-tech-spec.md"
 
           git clone --depth 1 \
             "https://x-access-token:${GH_TOKEN}@github.com/${REGISTRY}.git" \
             registry
 
           cd registry
+
+          if [ ! -f "$TARGET" ]; then
+            echo "::error::Canonical spec path $TARGET not found in registry. Check MANIFEST.json."
+            exit 1
+          fi
+
           git checkout -b "$BRANCH"
-          mkdir -p "$(dirname "$TARGET")"
           cp "../source/docs/${SPEC_KEY}-tech-spec.md" "$TARGET"
 
           git config user.name "sparxstar-contract-sync[bot]"