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).

internal/database/migrations/0002_seed.sql

@@ -14,7 +14,7 @@ INSERT INTO settings (key, value) VALUES
     ('asset_id_prefix', 'IT-'),
     ('asset_id_padding', '6'),
     ('asset_id_seq', '0'),
-    ('site_name', 'inventree');
+    ('site_name', 'vibetree');
 
 INSERT INTO item_types (name, description, icon, enabled, sort_order) VALUES
     ('Laptop', 'Portable computer', 'bi-laptop', 1, 1),