HFI: PDF Station Ordering

**Describe the Bug**
Station order within planning centres are not respected in the generated PDFs.

**Expected Behaviour**
Station order within PDFs should match the HFI calc page, which uses the `order_of_appearance_in_planning_area_list` field to order stations

**Actual Behaviour**
Stations are not ordered according `order_of_appearance_in_planning_area_list` in generated PDFs

** Steps To Reproduce**
Steps to reproduce the behaviour:
1. Go to HFI Calculator
2. Click on Kamloops Fire Centre
3. Scroll down to Vernon planning area
4. See station, "Bay Station 2" 3rd in list
5. Click Download PDF
6. Scroll to Vernon planning area
4. See station, "Bay Station 2" last in list

**Screenshots**
If applicable, add screenshots to help explain your problem.

**Desktop (please complete the following information):**
- OS: [e.g. iOS]
- Browser [e.g. chrome, safari]
- Version [e.g. 22]

**Additional context**
Add any other context about the problem here.

Start at the HFI Calculator entry point and trace the Download PDF path, comparing its station ordering with the HFI calc page's order_of_appearance_in_planning_area_list field. Reproduce the Vernon planning-area case with Bay Station 2, then verify that the generated PDF matches the calculator order.

Written by the indexing model from the issue text.