Observability dashboard: audit trail, activity timeline, memory browser

[kovtcharov]

Summary

The Agent UI observability dashboard shows what the agent DID. Separate from the configuration dashboard (what the agent CAN do).

Components

• Audit trail — all tool executions logged to SQLite with who/what/when/result
• Agent activity timeline — sidebar timeline of agent actions, filterable by type
• Memory browser — view/edit stored knowledge from the memory system
• Token usage — tokens processed, cost savings vs cloud equivalents
• Session history — past conversations with search
• Tool execution history — success/failure rates per tool

Key Requirements

• Audit logging active even in dangerous mode (Dangerous mode: opt-in guardrail bypass for autonomous execution #559)
• Exportable audit logs for enterprise compliance
• Memory browser allows users to review and edit what the agent "knows"
• Token usage shows equivalent cloud cost savings

Acceptance Criteria

• All tool executions logged to ~/.gaia/audit.db
• Audit log viewable in Agent UI observability panel
• CLI: gaia audit list, gaia audit export
• Agent activity timeline in sidebar
• Memory browser shows stored facts with edit capability
• Token usage dashboard with cost savings telemetry

Dependencies

• MemoryStore: persistent memory data layer (SQLite + FTS5) #542 (MemoryStore)
• Memory Dashboard API: REST endpoints for observability #574 (Memory Dashboard API)
• Memory Dashboard UI: knowledge browser, tool stats, activity timeline #575 (Memory Dashboard UI)