feat(FN-3321): add agent self-improvement service and heartbeat evaluation

This merge delivers agent self-improvement (FN-3321) — adding evaluation identity tools, wiring evaluation into the heartbeat loop, implementing a self-improvement service, and providing test coverage. It also expands the dashboard guide view with regression tests, adds org chart full-view mode with

Fusion-Task-Id: FN-3321

.changeset/agent-self-improvement.md

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+---
+"@runfusion/fusion": minor
+---
+
+Add agent self-improvement tools (fn_read_evaluations, fn_update_identity) and periodic self-improvement scheduling based on evaluation feedback.