Move the DebugSignalGraph, DebugSignalGraphEdge, and DebugSignalGraphNode interfaces from packages/core/src/render3/util/signal_debug.ts into the packages/core/primitives/devtools/src package. This decouples the signal graph debug types from runtime render3 utilities and allows devtools and internal core tooling to import them directly from primitives as type-only exports.
(cherry picked from commit d997a96b47)
Extract the AI tool definition interfaces from the core debug module to the devtools primitives module. This relocates ToolDefinition, ToolGroup, and DevtoolsToolDiscoveryEvent to the primitives folder, exposing them cleanly via "export type" in the devtools entry point, improving module organization and readability.
(cherry picked from commit bf6dba878e)