feat(tenancy): add profile editing in merchant team edit modal

Edit modal now has editable first_name, last_name, email fields with
a "Save Profile" button, alongside the existing per-store role management.

New:
- PUT /merchants/account/team/members/{user_id}/profile endpoint
- MerchantTeamProfileUpdate schema
- update_team_member_profile() service method with ownership validation
- 2 new i18n keys across 4 locales (personal_info, save_profile)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/tenancy/schemas/team.py

@@ -401,3 +401,11 @@ class MerchantTeamInviteResponse(BaseModel):
     message: str
     email: EmailStr
     results: list[MerchantTeamInviteResult]
+
+
+class MerchantTeamProfileUpdate(BaseModel):
+    """Schema for updating a team member's profile."""
+
+    first_name: str | None = Field(None, max_length=100)
+    last_name: str | None = Field(None, max_length=100)
+    email: EmailStr | None = None