feat(state-hub): v0.3 registration workflow + ingest-sbom + CLAUDE.md template update

- scripts/ingest_sbom.py: lockfile parser + API poster for uv.lock, requirements.txt,
  package-lock.json, yarn.lock, Cargo.lock; auto-detects from repo root
- Makefile: make ingest-sbom REPO=<slug> [LOCKFILE=<path>] target
- scripts/register_project.sh: adds {REPO_SLUG} template substitution + optional
  SBOM ingest prompt at end of registration (non-fatal if venv not ready)
- scripts/project_claude_md.template: adds Contribution Tracking + SBOM sections
  documenting register_contribution(), update_contribution_status(), ingest-sbom,
  and the contrib/ directory layout
- workplans/CUST-WP-0002: all 15 tasks → done, status → completed

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

state-hub/scripts/register_project.sh

@@ -126,6 +126,7 @@ else
         -e "s|{PROJECT_NAME}|$PROJECT_NAME|g" \
         -e "s|{DOMAIN}|$DOMAIN|g" \
         -e "s|{TOPIC_ID}|$TOPIC_ID|g" \
+        -e "s|{REPO_SLUG}|$REPO_SLUG|g" \
         "$TEMPLATE" > "$CLAUDE_MD"
     echo "    Written."
 fi
@@ -186,3 +187,21 @@ echo "  Repo slug: $REPO_SLUG"
 echo "  CLAUDE.md: $CLAUDE_MD"
 echo ""
 echo "Next: restart Claude Code for the MCP server to be available in this project."
+
+# ── Optional: SBOM ingest ─────────────────────────────────────────────────────
+if [[ "$ADDITIONAL" != "--additional" ]]; then
+    echo ""
+    read -r -p "==> Run SBOM ingest now? (auto-detects lockfile in $PROJECT_PATH) [y/N] " INGEST_NOW
+    if [[ "$INGEST_NOW" =~ ^[Yy]$ ]]; then
+        echo "==> Ingesting SBOM for '$REPO_SLUG' ..."
+        INGEST_UV="$STATE_HUB_DIR/.venv/bin/python"
+        if [[ -x "$INGEST_UV" ]]; then
+            "$INGEST_UV" "$SCRIPT_DIR/ingest_sbom.py" \
+                --repo "$REPO_SLUG" \
+                --repo-path "$PROJECT_PATH" \
+                --api-base "$API_BASE" && echo "    SBOM ingested." || echo "    SBOM ingest failed (non-fatal)."
+        else
+            echo "    Skipping: .venv not found. Run 'make install' first, then 'make ingest-sbom REPO=$REPO_SLUG'."
+        fi
+    fi
+fi