Project configuration view: manage a project's statuses

New /projects/:id/configure view, linked from a new 'Configure' item on
the project view's Manage menu.

Backend:
- CardStatusRepository/CardStatusController gain full CRUD: create
  (appended at the end), reorder (dense positions, like card
  ordering), and delete.
- Deleting a status with cards attached is rejected with 409 and
  error.details.card_count, rather than hitting the existing FK
  RESTRICT constraint -- retrying with { reassign_to: <status id> }
  moves those cards to that status first (CardRepository::
  reassignStatus, appended after the destination's existing cards)
  and deletes in one transaction (CardStatusRepository::transaction,
  shared PDO connection across repositories).
- The last status in a project can't be deleted, since a project card
  is required to have one.
- Routes: POST/DELETE .../statuses(/:id), PUT .../statuses/order.
- 14 new CardStatusTest cases covering all of the above.

Frontend:
- ProjectConfigureView.vue: header (title, back-to-project link, the
  shared Manage menu) + a vuedraggable status list (reorder persists
  the whole new order) with a delete button per row and an add-status
  form. A row's plain delete either succeeds immediately or, on 409,
  opens a modal to choose a different status before retrying the
  delete with reassign_to.
- Extracted ProjectManageMenu.vue (the Manage dropdown + delete-project
  modal) out of ProjectView so both views share it; it now also has a
  Configure link (hidden on the configure page itself).
- ApiError gains a cardCount getter (details.card_count), mirroring
  the existing retryAfter getter.

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

web/src/style.css

@@ -508,6 +508,13 @@ h1 {
   background: var(--bg);
 }
 
+.project-head__back {
+  display: inline-flex;
+  align-items: center;
+  flex: none;
+  text-decoration: none;
+}
+
 .menu {
   position: relative;
   flex: none;
@@ -553,6 +560,7 @@ h1 {
   display: block;
   width: 100%;
   text-align: left;
+  text-decoration: none;
   border: none;
   background: none;
   color: var(--text);
@@ -604,6 +612,108 @@ h1 {
   max-width: 42rem;
 }
 
+/* --- project configuration: status list ------------------------------- */
+
+.config-section {
+  max-width: 32rem;
+  margin-top: 1.5rem;
+}
+
+.config-section h2 {
+  margin: 0 0 0.25rem;
+  font-size: 1.1rem;
+}
+
+.status-list {
+  list-style: none;
+  margin: 1rem 0 0;
+  padding: 0;
+  display: grid;
+  gap: 0.4rem;
+}
+
+.status-row {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 0.5rem 0.6rem;
+  background: var(--surface);
+  cursor: grab;
+}
+
+.status-row--ghost {
+  opacity: 0.5;
+}
+
+.status-row__name {
+  flex: 1;
+  min-width: 0;
+  word-break: break-word;
+}
+
+.status-row__delete {
+  flex: none;
+  border: none;
+  background: none;
+  color: var(--muted);
+  cursor: pointer;
+  font-size: 1rem;
+  padding: 0.2rem 0.4rem;
+  border-radius: 6px;
+}
+
+.status-row__delete:hover:not(:disabled) {
+  color: var(--error);
+}
+
+.status-row__delete:disabled {
+  opacity: 0.4;
+  cursor: not-allowed;
+}
+
+.status-list__new {
+  display: flex;
+  gap: 0.4rem;
+  margin-top: 0.75rem;
+}
+
+.status-list__new input {
+  flex: 1;
+  min-width: 0;
+  font: inherit;
+  font-size: 0.9rem;
+  padding: 0.4rem 0.5rem;
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  background: var(--bg);
+  color: var(--text);
+}
+
+.status-list__new button[type='submit'] {
+  flex: none;
+  padding: 0.4rem 0.7rem;
+  font-size: 0.9rem;
+  border-radius: 6px;
+}
+
+.modal__field {
+  display: grid;
+  gap: 0.3rem;
+  font-size: 0.9rem;
+  margin-top: 0.75rem;
+}
+
+.modal__field select {
+  padding: 0.5rem 0.6rem;
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  background: var(--bg);
+  color: var(--text);
+  font: inherit;
+}
+
 /* --- kanban board ---------------------------------------------------- */
 
 .kanban {