fix(memory): support arbitrary Qdrant document ids

[EmersonBraun]

Summary

• map arbitrary vector document IDs to deterministic Qdrant-compatible UUIDs
• preserve safe numeric IDs and valid UUIDs
• restore original source IDs on search and use the same mapping on delete
• keep adapter metadata internal
• add the required patch changeset

Root cause

Qdrant accepts point IDs only as unsigned integers or UUIDs. AgentsKit RAG creates
chunk IDs such as doc-1_chunk_0, which the Qdrant adapter previously forwarded
unchanged and Qdrant rejected with HTTP 400.

Validation

• pnpm --filter @agentskit/core build
• pnpm --filter @agentskit/memory test — 209 passed
• pnpm --filter @agentskit/memory lint
• pnpm --filter @agentskit/memory build
• live Qdrant 1.15.4 proof stored, restored, and deleted doc-1_chunk_0
• git diff --check

This draft does not authorize merge, release, tag, npm publication, or the external
Qdrant example pull request.