Add AI Development tag to ai-powered-phone-system in consulting index (#4490)

The ai-powered-phone-system page was not appearing in the AI Development
filter on `/consulting` because it lacked the `tags` property in
`index.json`. The frontend filtering logic requires this property to
match pages to categories.

**Changes:**
- Added `tags` array with `ai-development.json` reference to
ai-powered-phone-system entry
- Added `externalUrl` property for consistency with other consultingv2
pages (local-llm-deployment, vibe-coding, ai-discovery-workshop)

```json
{
  "title": "AI-Powered Phone System",
  "page": "content/consultingv2/ai-powered-phone-system.json",
  "externalUrl": "/consulting/ai-powered-phone-system",
  "tags": [
    {
      "tag": "content/consulting/tag/ai-development.json"
    }
  ]
}
```

- Affected routes: `/consulting`, `/consulting?tag=AI-Development`

- [ ] If adding a new page, I have followed the [📃 New
Webpage](https://github.com/SSWConsulting/SSW.Website/issues/new?assignees=&labels=&projects=&template=new_webpage.yml&title=%F0%9F%93%84+%7B%7B+TITLE+%7D%7D+)
issue template

- [ ] If updating the livestream banner, I have tested and followed the
steps in [Wiki - Testing the live
banner](https://github.com/SSWConsulting/SSW.Website/wiki/Testing-the-live-banner)

- [ ] Include Done Video or screenshots

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<details>

<summary>Original prompt</summary>

> 
> ----
> 
> *This section details on the original issue you should resolve*
> 
> <issue_title>🐛 {{ TITLE }} SSW Consulting index - Add new consulting
page to the AI Development category</issue_title>
> <issue_description>**Describe the bug**
> On https://www.ssw.com.au/consulting, when I click on "AI Development"
I expect to see the section relating to
https://www.ssw.com.au/consulting/ai-powered-phone-system in the filter
> 
> **To Reproduce**
> 1. go to https://www.ssw.com.au/consulting
> 2. click on the AI Development category
> 
> **Expected behavior**
> the filtered list includes the
https://www.ssw.com.au/consulting/ai-powered-phone-system section
> 
> **Screenshots/Video**
> If applicable, add screenshots/video to help explain your problem.
> Remember to mark the area in the application thats impacted.
> </issue_description>
> 
> ## Comments on the Issue (you are @copilot in this section)
> 
> <comments>
> </comments>
> 


</details>



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- Fixes #4489

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: uly1 <162542237+uly1@users.noreply.github.com>

Author: Copilot

content/consulting/index/index.json

@@ -159,7 +159,13 @@
           "title": "AI-Powered Phone System",
           "description": "Turn your phone system into an Intelligent 24/7 conversational assistant that automates inbound and outbound calls, improves customer experience, reduce wait times",
           "logo": "/images/thumbs/Generated%20image%20final.png",
-          "page": "content/consultingv2/ai-powered-phone-system.json"
+          "page": "content/consultingv2/ai-powered-phone-system.json",
+          "externalUrl": "/consulting/ai-powered-phone-system",
+          "tags": [
+            {
+              "tag": "content/consulting/tag/ai-development.json"
+            }
+          ]
         }
       ]
     },