Rename project from inventree to vibetree

- go.mod module path (and every internal/vibetree import) inventree -> vibetree
- cmd/inventree/ -> cmd/vibetree/, deploy/inventree.service -> vibetree.service
- Default site name (seed data + the siteName template func's fallback)
  is now "vibetree", shown in the navbar, <title>, and login page
- Session cookie renamed inventree_session -> vibetree_session
- Default DB path data/inventree.db -> data/vibetree.db, CLI/log text,
  Dockerfile, docker-compose.yml, README, .gitignore/.dockerignore all
  updated to match

Existing installs: this changes the session cookie name (users will be
signed out once) and the default DB filename (point -db at your existing
file, or rename it, to keep your data).

docker-compose.yml

@@ -1,13 +1,13 @@
 services:
-  inventree:
+  vibetree:
     build: .
-    image: inventree:latest
-    container_name: inventree
+    image: vibetree:latest
+    container_name: vibetree
     restart: unless-stopped
     ports:
       - "8080:8080"
     volumes:
-      - inventree-data:/app/data
+      - vibetree-data:/app/data
     healthcheck:
       test: ["CMD", "wget", "-qO-", "http://127.0.0.1:8080/healthz"]
       interval: 30s
@@ -16,4 +16,4 @@ services:
       start_period: 5s
 
 volumes:
-  inventree-data:
+  vibetree-data: