feat: surface edge counts in graph_search and graph_get

[Evanfeenstra]

What

graph_search and graph_get (the Jarvis knowledge-graph tools agents use to traverse the graph) now include an edges map per node showing edge type → count:

{
  "ref_id": "abc-123",
  "node_type": "File",
  "name": "main.rs",
  "edges": { "CONTAINS": 5, "PART_OF": 4 }
}

Why

Lets an agent see how connected a node is and which relationship types it can hop along next (via graph_neighbors) directly from search/get results — no separate exploratory call needed to gauge connectivity.

How

• graph_search: sends include_edge_counts=true so Jarvis attaches the edges map inline. One call, no per-node round trips.
  • Depends on stakwork/jarvis-backend#2976 (adds that param). Until it deploys, graph_search results simply carry edges: {}.
• graph_get: calls the existing /v2/nodes/{ref_id}/connection-counts endpoint and collapses its (edge_type, target_type, count) rows into {EDGE_TYPE: count} via the new exported collapseConnectionCounts helper. Works today (endpoint already exists). Adds an optional namespace param so the count is scoped to the right partition. Best effort — never fails the call if the lookup errors.

Tests

• New unit tests for collapseConnectionCounts (summing across target types, missing/non-numeric counts, empty input).
• Updated graph_search URL-construction tests to assert include_edge_counts=true.
• All 25 tests in toolsJarvis.test.ts pass; tsc --noEmit clean.