feat(settings): complete remaining settings tabs (account, tags, turns)

Fill the three previously-placeholder settings sections so every menu item
is now a real page inside the settings shell:

- حساب کاربری: new authenticated POST /api/v1/user/change-password
  (verifies current password, ≥8 chars, must differ) + account page with a
  profile summary and change-password form.
- برچسب‌ها: new per-tenant TenantTag domain (entity/repo/controller +
  migration) with tenant-scoped CRUD at /api/v1/tenant-tag(s), plus a tags
  management page (list + color + add/edit/delete).
- مدیریت نوبت دهی: export the existing WeeklyScheduleTab from
  DoctorDetailPage and reuse it in a standalone AppointmentSettingsPage
  (current doctor's uuid + addresses).

Wire all three menu entries to their routes. Backend covered by PHPUnit
(change-password, tenant-tag CRUD + ownership); FE covered by Vitest.
API docs updated (auth.md, tag.md).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/Tag/Entity/TenantTag.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace App\Tag\Entity;
+
+use App\Tag\Repository\TenantTagRepository;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Uid\Uuid;
+
+/**
+ * A per-tenant (doctor/clinic) label with a display color. Distinct from the
+ * global slug-based {@see Tag} taxonomy — these are owned and managed by each
+ * tenant for their own use (e.g. patient/appointment labelling).
+ */
+#[ORM\Entity(repositoryClass: TenantTagRepository::class)]
+#[ORM\Table(name: 'tenant_tags')]
+#[ORM\Index(columns: ['entity_type', 'entity_id'], name: 'idx_tenant_tags_owner')]
+class TenantTag
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column(type: 'integer')]
+    private ?int $id = null;
+
+    #[ORM\Column(type: 'string', length: 36, unique: true)]
+    private string $uuid;
+
+    #[ORM\Column(name: 'entity_type', type: 'string', length: 20)]
+    private string $entityType;
+
+    #[ORM\Column(name: 'entity_id', type: 'integer')]
+    private int $entityId;
+
+    #[ORM\Column(type: 'string', length: 60)]
+    private string $name;
+
+    /** Hex color, e.g. "#5559CE". */
+    #[ORM\Column(type: 'string', length: 9)]
+    private string $color = '#5559CE';
+
+    #[ORM\Column(type: 'boolean')]
+    private bool $active = true;
+
+    #[ORM\Column(name: 'created_at', type: 'integer')]
+    private int $createdAt;
+
+    #[ORM\Column(name: 'updated_at', type: 'integer')]
+    private int $updatedAt;
+
+    public function __construct(string $entityType, int $entityId, string $name, string $color = '#5559CE')
+    {
+        $this->uuid       = Uuid::v4()->toRfc4122();
+        $this->entityType = $entityType;
+        $this->entityId   = $entityId;
+        $this->name       = $name;
+        $this->color      = $color;
+        $this->createdAt  = time();
+        $this->updatedAt  = time();
+    }
+
+    public function getId(): ?int           { return $this->id; }
+    public function getUuid(): string       { return $this->uuid; }
+    public function getEntityType(): string { return $this->entityType; }
+    public function getEntityId(): int      { return $this->entityId; }
+    public function getName(): string       { return $this->name; }
+    public function getColor(): string      { return $this->color; }
+    public function isActive(): bool        { return $this->active; }
+
+    public function setName(string $v): self   { $this->name = $v; $this->updatedAt = time(); return $this; }
+    public function setColor(string $v): self  { $this->color = $v; $this->updatedAt = time(); return $this; }
+    public function setActive(bool $v): self   { $this->active = $v; $this->updatedAt = time(); return $this; }
+
+    public function toArray(): array
+    {
+        return [
+            'uuid'   => $this->uuid,
+            'name'   => $this->name,
+            'color'  => $this->color,
+            'active' => $this->active,
+        ];
+    }
+}