GAP-L1-P1-repo-graph-discovery-signal

Current state

The repo's live packages/agent-catalog/graph/schema/ontology-schema.yaml defines DiscoverySignal (with signalKind, key, matchMode, confidence, argvMatches, etc.) and a discovered_by edge. v6 graph treats discovery as out-of-scope ("Discovery runtime queries (detectHostAgent, listInstalledAgents)... runtime API; the catalog *describes* the data such queries consume; the queries themselves are not schema").

But discovery **signals** themselves (file patterns, env-var names, argv shapes that identify a host agent) ARE catalog data — and the live repo proves it. Coverage-checklist row "Discovery (concept)" maps to DiscoverySignal but no NodeKind by that name exists in v6 ontology-schema.yaml.

Desired state

Promote DiscoverySignal to a first-class NodeKind in v6 schema, with attributes mirrored from the repo: signalKind (enum<env-var,file-presence,argv-match,pkg-manifest>), key, matchMode, confidence, scope, argvMatches. Add edge AgentVersion discovered_by DiscoverySignal (and similarly for ModelProviderVersion, PluginTarget).

Evidence

• packages/agent-catalog/graph/schema/ontology-schema.yaml (lines 172-182)
• packages/agent-catalog/graph/nodes/agents/ (live signal data)
• C:/work/v6/graph/coverage-checklist.md "Discovery (concept)" row references DiscoverySignal as if it exists

Propagation status

• Level 1: open
• Level 2: not-started — coverage-checklist row currently false-positive (✅ but no schema element)

Propagation chain

• Level 1: add NodeKind + edge in ontology-schema.yaml.
• Level 2: this resolves OpenQuestion "How do live agent-catalog 22 NodeKinds collapse into v6 schema NodeKinds?" partially.

Notes

Closes coverage-checklist OpenQuestion oq:repo-22-nodekinds-mapping for one of the missing kinds.