Simplify the project view header: drop the back link and description

- Remove the '<- All projects' link at the top -- the sidebar's
  Dashboard link already covers that.
- Remove the description textarea and all of its state/save logic
  (descriptionDraft, saveDescription, patchProject's description
  field); the backend field and API are untouched.
- Drop .project__chrome's 42rem max-width, which existed only to keep
  the now-gone description prose readable. The header (title + Manage
  menu) now spans the full wide-layout width, so Manage sits at the
  true top right instead of a narrower centred column.

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

web/README.md

@@ -80,11 +80,11 @@ under the list adds a card straight to the inbox.
 ## Project detail
 
 `/projects/:id` shows one project. It renders on a **full-width** layout (the
-route sets `meta.wide`, which widens `.app__main` in `App.vue`). The title and
-description are inline-editable (saved on blur via `PATCH /api/projects/:id`; the
-description shows an "Add a description" placeholder when empty). A **Manage**
-menu (top right) has a **Delete project** action that opens a confirmation modal;
-confirming calls `DELETE /api/projects/:id` and returns to the dashboard.
+route sets `meta.wide`, which widens `.app__main` in `App.vue`), so the header
+spans the full width and the **Manage** menu sits top right. The title is
+inline-editable (saved on blur via `PATCH /api/projects/:id`). Manage has a
+**Delete project** action that opens a confirmation modal; confirming calls
+`DELETE /api/projects/:id` and returns to the dashboard.
 
 Below the header are two tabs (local `activeTab` state, `v-show` so both stay
 mounted). The tab order is fixed — **All tasks** first, **Kanban** second — but