Tech Debt: `ToolRegistry` — Shared Mutable State Across Concurrent Agent Executions [RESOLVED]

Status: Resolved (2026-08-12)
Commit: 2ac652d
Resolution: Per-agent AgentToolScope instances with scoped tool loading and execution. URLClassLoader lifecycle managed via evictAgent(). Builtin tools shared as read-only base. Backward-compatible global getAvailableToolNames() / findTool() kept for Embabel interoperability.

Resolution Summary

Change	Detail
`AgentToolScope` inner class	Per-agent `tools`, `providers`, `classLoaders` maps — full isolation
Scoped `loadToolSources`	`loadToolSources(String agentName, List<ToolSource>)` — loads into agent's scope
Scoped `executeActiveTools`	`executeActiveTools(String agentName, ...)` — executes only agent's tools
`evictAgent(agentName)`	Closes all `URLClassLoader` instances; removes scope from registry
`@PreDestroy` cleanup	Evicts all agent scopes on shutdown
Global union fallback	`getAvailableToolNames()` / `findTool()` union all scopes — Embabel `TuluatToolGroup` compat
Builtin tools	Calculator, WebSearch, Weather shared as read-only base; copied into each new scope
Caller updates	`AgentExecutionService.processAgentPrompt()` + `invokeResolvedAgent()` pass `agentName`

Problem	Detail
Accumulation without eviction	Tools added but never removed on AiAgent CR deletion or toolSources change.
No agent-level isolation	Agent A's custom JAR tool visible to Agent B; any agent could invoke any tool.
Redundant JAR classloading	`loadFromFolder()` called on every execution; same JARs reloaded repeatedly.
`URLClassLoader` leak	Each `LoadedProvider` created new `URLClassLoader`; never closed → metaspace pressure.
Race on `loadedProviders` map	Concurrent agent executions could flip `loadedProviders` entries mid-flight.