get_record does not support epic references (e.g. DCOMMS-E-157)

[BeyondRoadmap]

Bug / Feature Request

get_record rejects epic reference numbers with an InvalidParams error:

get_record({ reference: "DCOMMS-E-157" })
// → "Invalid reference number format. Expected DEVELOP-123 or ADT-123-1"

Expected behavior

Epic references (PRODUCT-E-123) should resolve the same way features and
requirements do — returning the epic's name and description body.

Current workaround

search_documents with searchableType: "Epic" already works and returns
valid epic references, but only name/URL metadata — not the body content.
There is no way to read an epic's description through the current MCP tools.

Proposed fix

1. Add EPIC_REF_REGEX = /^([A-Z][A-Z0-9]*)-E-(\d+)$/ to types.ts
2. Add EpicResponse interface to types.ts
3. Add getEpicQuery to queries.ts (mirrors getFeatureQuery using the epic(id) GraphQL resolver)
4. Add epic branch in handleGetRecord in handlers.ts
5. Update get_record description in index.ts

The regex does not conflict with existing patterns — features use PRODUCT-123 (digits only), requirements use PRODUCT-123-1 (two numeric segments), and epics use PRODUCT-E-123 (literal E segment).

Happy to submit a PR if this approach looks good to maintainers.