AI Assistant Refinements & Observability Cleanup

Refactored observability by dropping tool performance metrics and usage scenarios. Tool counts now track from tool calls and last usage instead of joining specific metric tables.

The frontend brain panel has been simplified to display tools as a count and last-used table. Tests were updated to reflect the new endpoint shape.

The structure of the user prompt was changed to place the user summary earlier, anchoring it for recency. This moved getUserDefinition() injection to getUserPrompt() before World State.

Architecture documentation was updated to remove references to the knowledge table and optional profile enrichment features.

The KnowledgeService and its associated knowledge table were removed entirely, as all recall now routes through DataGraphService.

Various downstream cleanups removed wires related to deleted services like event-bridge, invocation-tracker, profile-enrichment, and tool-performance.

The tool profile schema was simplified by removing usage_scenarios and triage_triggers fields.

Telemetry tracking was updated to persist the frontend heartbeat dynamically to a new telemetry table, making the frontend the source of truth for keys.

• Frontend tools view simplified to count/last-used table.

• Tool counts now derived from tool calls and last used status.

• User summary moved to the prompt for recency anchoring.

• KnowledgeService and legacy knowledge table were fully removed.

• Telemetry now relies on a dynamic FE heartbeat persisting to a new table.

• Removed references to several decommissioned services.