WorkGraph production features

[G9Pedro]

Implement thread context store, webhook event deduplication, and standalone thread creation to improve WorkGraph's production usage and reliability.

This PR addresses three key areas:

1. Thread Context Store: Adds per-thread searchable context, including wg_thread_context_add, wg_thread_context_search, wg_thread_context_list, wg_thread_context_prune MCP tools, and a context summary in workgraph_thread_claim responses, enabling agents to retrieve relevant thread-specific information.
2. Webhook Event Deduplication: Introduces deliveryId and payloadDigest based deduplication in the webhook gateway with a bounded LRU cache, preventing duplicate processing of redelivered GitHub webhooks.
3. Standalone Thread Creation: Adds a new wg_create_thread MCP tool, allowing the creation of top-level threads without requiring a parent, enhancing thread management flexibility.

  

[cursor]

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[G9Pedro]

🐘 Code Review — Approved

Clean PR. Three well-scoped production features with tests for each:

Thread Context Store — BM25 search, add/list/search/prune/summarize. Context summary auto-injected on thread_claim (good agent UX). Solid normalization and frontmatter handling throughout.

Webhook Dedup — In-memory LRU with TTL (5min, 1000 entries). Checks deliveryId then payloadDigest fallback. Acceptable for GitHub retry protection — resets on restart but retries happen within minutes.

Standalone Thread Creation — wg_create_thread with idempotency key + replay conflict detection. Proper auth gates (thread:create + mcp:write).

CI failure is pre-existing — all errors in tests/stress/*.test.ts (missing tsconfig path mappings for @versatly/workgraph-kernel). Not caused by this PR.

Ready to merge. 👍