Rename the app from tracker to fit

The directory, the repo and the hostname are all fit; the module path,
the image, the namespace and the data file were still tracker. Nothing
is deployed yet, so this is free now and would not be later.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitea/workflows/deploy.yaml

@@ -30,12 +30,12 @@ jobs:
 
       - name: Build image
         run: |
-          IMAGE=harbor.scottyah.com/scottyah/tracker
+          IMAGE=harbor.scottyah.com/scottyah/fit
           buildah --isolation chroot bud -t $IMAGE:${{ github.sha }} -t $IMAGE:latest .
 
       - name: Push image
         run: |
-          IMAGE=harbor.scottyah.com/scottyah/tracker
+          IMAGE=harbor.scottyah.com/scottyah/fit
           # Harbor serves a publicly trusted certificate, so TLS is verified.
           # Disabling verification would send these credentials, and accept the
           # image, over a connection nothing has authenticated.
@@ -52,6 +52,6 @@ jobs:
           chmod +x kubectl
           mkdir -p ~/.kube
           echo "${{ secrets.KUBECONFIG_DATA }}" | base64 -d > ~/.kube/config
-          sed -i "s|harbor.scottyah.com/scottyah/tracker:latest|harbor.scottyah.com/scottyah/tracker:${{ github.sha }}|" k8s.yaml
+          sed -i "s|harbor.scottyah.com/scottyah/fit:latest|harbor.scottyah.com/scottyah/fit:${{ github.sha }}|" k8s.yaml
           ./kubectl apply -f k8s.yaml
-          ./kubectl rollout status deployment/tracker-dep -n tracker --timeout=120s
+          ./kubectl rollout status deployment/fit-dep -n fit --timeout=120s