feat: add tags workflow

README.md

@@ -14,7 +14,8 @@ cloud, no server: git-friendly, editable in any editor.
 - **Dashboard** — task list + description (filters, scope, sort, group)
 - **Kanban** — status columns, drag-and-drop, create-in-column
 - **Commands** — create / open / change status / delete
-- **In-editor** — frontmatter lint + status/priority Quick Pick (decorations)
+- **In-editor** — frontmatter lint + status/priority/tags/assignee actions
+- **Project tags** — catalog in task folder `config.yml`
 - **Two stores** — project folder (workspace) and global folder (shared on the
   machine)
 
@@ -119,6 +120,26 @@ Task description in markdown…
 One file per task (`*.xflow.md`). File name is derived from the title (slug).
 `title` max length: 80 characters.
 
+### Project config (`config.yml` in the task folder)
+
+Default layout:
+
+```text
+.xflow/
+  config.yml          # project tags catalog
+  fix-login.xflow.md
+```
+
+```yaml
+# .xflow/config.yml
+tags:
+  - bug
+  - frontend
+```
+
+If `config.yml` exists, tags on a task that are **not** in the catalog show as
+warnings. Hover `tags` → **Edit tags…** / **Add tag to project**.
+
 ## Dashboard
 
 - Search title/body; status/priority chips; group none/status/priority