Tests and AGENTS.md updated

AGENTS.md

@@ -214,10 +214,9 @@ labhelper/
 │   │       ├── add_things.html             # Form to add multiple things
 │   │       ├── box_detail.html             # Box contents view
 │   │       ├── box_management.html         # Box/BoxType CRUD management
-│   │       ├── index.html                  # Home page
+│   │       ├── index.html                  # Home page with boxes and tags
 │   │       ├── search.html                 # Search page with AJAX
-│   │       ├── thing_detail.html           # Thing details view
-│   │       └── thing_type_detail.html      # Thing type hierarchy view
+│   │       └── thing_detail.html           # Thing details view with tags
 │   ├── templatetags/
 │   │   └── dict_extras.py                  # Custom template filter: get_item
 │   ├── admin.py                            # Admin configuration
@@ -259,19 +258,24 @@ labhelper/
 |-------|-------------|------------|
 | **BoxType** | Type of storage box with dimensions | `name`, `width`, `height`, `length` (in mm) |
 | **Box** | A storage box in the lab | `id` (CharField PK, max 10), `box_type` (FK) |
-| **ThingType** | Hierarchical category (MPTT) | `name`, `parent` (TreeForeignKey to self) |
-| **Thing** | An item stored in a box | `name`, `thing_type` (FK), `box` (FK), `description`, `picture` |
+| **Facet** | A category of tags (e.g., Priority, Category) | `name`, `slug`, `color`, `cardinality` (single/multiple) |
+| **Tag** | A tag value for a specific facet | `facet` (FK), `name` |
+| **Thing** | An item stored in a box | `name`, `box` (FK), `description`, `picture`, `tags` (M2M) |
 | **ThingFile** | File attachment for a Thing | `thing` (FK), `file`, `title`, `uploaded_at` |
 | **ThingLink** | Hyperlink for a Thing | `thing` (FK), `url`, `title`, `uploaded_at` |
 
 **Model Relationships:**
 - BoxType -> Box (1:N via `boxes` related_name, PROTECT on delete)
 - Box -> Thing (1:N via `things` related_name, PROTECT on delete)
-- ThingType -> Thing (1:N via `things` related_name, PROTECT on delete)
-- ThingType -> ThingType (self-referential tree via MPTT)
+- Facet -> Tag (1:N via `tags` related_name, CASCADE on delete)
+- Thing <-> Tag (M2M via `tags` related_name on Thing, `things` related_name on Tag)
 - Thing -> ThingFile (1:N via `files` related_name, CASCADE on delete)
 - Thing -> ThingLink (1:N via `links` related_name, CASCADE on delete)
 
+**Facet Cardinality:**
+- `single`: A thing can have at most one tag from this facet (e.g., Priority: High/Medium/Low)
+- `multiple`: A thing can have multiple tags from this facet (e.g., Category: Electronics, Tools)
+
 ## Available Django Extensions
 
 The project includes these pre-installed packages:
@@ -371,7 +375,7 @@ The project uses a base template system at `labhelper/templates/base.html`. All
 
 | View Function | URL Pattern | Name | Description |
 |---------------|-------------|------|-------------|
-| `index` | `/` | `index` | Home page with boxes grid and thing types tree |
+| `index` | `/` | `index` | Home page with boxes grid and tags overview |
 | `box_management` | `/box-management/` | `box_management` | Manage boxes and box types |
 | `add_box_type` | `/box-type/add/` | `add_box_type` | Add new box type |
 | `edit_box_type` | `/box-type/<int:type_id>/edit/` | `edit_box_type` | Edit box type |
@@ -380,8 +384,7 @@ The project uses a base template system at `labhelper/templates/base.html`. All
 | `edit_box` | `/box/<str:box_id>/edit/` | `edit_box` | Edit box |
 | `delete_box` | `/box/<str:box_id>/delete/` | `delete_box` | Delete box |
 | `box_detail` | `/box/<str:box_id>/` | `box_detail` | View box contents |
-| `thing_detail` | `/thing/<int:thing_id>/` | `thing_detail` | View/edit thing (move, picture, files, links) |
-| `thing_type_detail` | `/thing-type/<int:type_id>/` | `thing_type_detail` | View thing type hierarchy |
+| `thing_detail` | `/thing/<int:thing_id>/` | `thing_detail` | View/edit thing (move, picture, files, links, tags) |
 | `add_things` | `/box/<str:box_id>/add/` | `add_things` | Add multiple things to a box |
 | `search` | `/search/` | `search` | Search page |
 | `search_api` | `/search/api/` | `search_api` | AJAX search endpoint |
@@ -434,7 +437,7 @@ The project uses a base template system at `labhelper/templates/base.html`. All
 
 | Form | Model | Purpose |
 |------|-------|---------|
-| `ThingForm` | Thing | Add/edit a thing (name, type, description, picture) |
+| `ThingForm` | Thing | Add/edit a thing (name, description, picture, tags) |
 | `ThingPictureForm` | Thing | Upload/change thing picture only |
 | `ThingFileForm` | ThingFile | Add file attachment |
 | `ThingLinkForm` | ThingLink | Add link |