rename: MeshCore Analyzer → CoreScope (Phase 1 — backend + infra)

Rename product branding, binary names, Docker images, container names,
Go modules, proto go_package, CI, manage.sh, and documentation.

Preserved (backward compat):
- meshcore.db database filename
- meshcore-data / meshcore-staging-data directory paths
- MQTT topics (meshcore/#, meshcore/+/+/packets, etc.)
- proto package namespace (meshcore.v1)
- localStorage keys

Changes by category:
- Go modules: github.com/corescope/{server,ingestor}
- Binaries: corescope-server, corescope-ingestor
- Docker images: corescope:latest, corescope-go:latest
- Containers: corescope-prod, corescope-staging, corescope-staging-go
- Supervisord programs: corescope, corescope-server, corescope-ingestor
- Branding: siteName, heroTitle, startup logs, fallback HTML
- Proto go_package: github.com/corescope/proto/v1
- CI: container refs, deploy path
- Docs: 8 markdown files updated

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/workflows/deploy.yml

@@ -303,7 +303,7 @@ jobs:
       - name: Start staging on port 82
         run: |
           # Force remove stale containers
-          docker rm -f meshcore-staging-go 2>/dev/null || true
+          docker rm -f corescope-staging-go 2>/dev/null || true
           # Clean up stale ports
           fuser -k 82/tcp 2>/dev/null || true
           docker compose --profile staging-go up -d staging-go
@@ -311,14 +311,14 @@ jobs:
       - name: Healthcheck staging container
         run: |
           for i in $(seq 1 120); do
-            HEALTH=$(docker inspect meshcore-staging-go --format '{{.State.Health.Status}}' 2>/dev/null || echo "starting")
+            HEALTH=$(docker inspect corescope-staging-go --format '{{.State.Health.Status}}' 2>/dev/null || echo "starting")
             if [ "$HEALTH" = "healthy" ]; then
               echo "Staging healthy after ${i}s"
               break
             fi
             if [ "$i" -eq 120 ]; then
               echo "Staging failed health check after 120s"
-              docker logs meshcore-staging-go --tail 50
+              docker logs corescope-staging-go --tail 50
               exit 1
             fi
             sleep 1
@@ -378,6 +378,6 @@ jobs:
           echo "To promote to production:" >> $GITHUB_STEP_SUMMARY
           echo "\`\`\`bash" >> $GITHUB_STEP_SUMMARY
           echo "ssh deploy@\$VM_HOST" >> $GITHUB_STEP_SUMMARY
-          echo "cd /opt/meshcore-deploy" >> $GITHUB_STEP_SUMMARY
+          echo "cd /opt/corescope-deploy" >> $GITHUB_STEP_SUMMARY
           echo "./manage.sh promote" >> $GITHUB_STEP_SUMMARY
           echo "\`\`\`" >> $GITHUB_STEP_SUMMARY