Context menu missing milestones on child entries

[jlunder00]

Bug

Milestones attached to child context entries (e.g. Tether/v3 LLM Redesign) don't appear in the context menu sidebar. They are only visible through the detail panels (task detail → milestone link, or navigating directly to the milestone).

Repro

1. Create a milestone on a child context entry (e.g. Tether/v3 LLM Redesign)
2. Open the context menu / context editor
3. Look at the parent entry (Tether) — no milestone indicator
4. Look at the child entry — no milestone shown either
5. Navigate to a task linked to that milestone via detail panel — milestone appears correctly there

Expected

The context menu should show milestones for child entries, either:

• Inline under the child entry, or
• As a rolled-up indicator on the parent entry showing "N milestones in subtree"

Context

Found while linking tasks to the new Tether/v3 LLM Redesign milestone via MCP tools. The milestone exists in the DB and is queryable via API/MCP, just not surfaced in the context UI.