feat: MCP dashboard-get should return tile IDs for use with dashboard-reorder-tiles

Is your feature request related to a problem?

The MCP dashboard-get tool returns tiles with their insight, order, color, layouts, last_refresh, and is_cached fields — but does not include the tile id.

The dashboard-reorder-tiles MCP tool requires tile IDs to reorder tiles on a dashboard. Its documentation says "First, use dashboard-get to retrieve the dashboard and see the current tile IDs", but those IDs aren't present in the response.

This means it's currently impossible to reorder dashboard tiles via the MCP tools — you can add an insight to a dashboard (and get back the new tile's ID from that response), but you can't reorder existing tiles because you don't know their IDs.

Describe the solution you'd like

Include the tile id field in each tile object returned by the dashboard-get MCP tool, e.g.:

tiles[3]:
  - id: 6012615       <-- add this
    insight:
      short_id: CIQ5WUyE
      ...
    order: 0
    ...

This would make dashboard-reorder-tiles usable as intended.

Describe alternatives you've considered

• Calling the PostHog REST API directly with curl to get tile IDs, then passing them to the MCP reorder tool — works but defeats the purpose of having MCP tools.
• Manually dragging tiles in the dashboard UI — works but not automatable.

Additional context

Discovered while trying to add a new insight to a dashboard via MCP and then move it to the end of the tile order. The add-insight-to-dashboard response does return the new tile's ID, but there's no way to discover IDs for pre-existing tiles.

Search the repository for the MCP dashboard-get and dashboard-reorder-tiles entry points, then inspect how dashboard tiles are assembled in the dashboard-get response. Include each tile's ID as shown in the issue and verify that the returned IDs can be passed to the reorder tool.