docs: implement CalendarAgent and FinanceAgent technical documentation and scheduling logic

[D3n3bX]

Description

This PR adds the comprehensive technical documentation for the CalendarAgent, the module responsible for managing Odoo Calendar operations.

Key Technical Implementations

• Temporal Normalization: Documented the agent's ability to transform natural language (e.g., 'tomorrow at 5') into standardized ISO timestamps for Odoo.
• Chronological Integrity: Detailed the past-date validation logic that prevents the assistant from scheduling retroactive meetings.
• HITL Scheduling: Explained the 'Human-in-the-Loop' workflow where Perry prepares a calendar invite and provides a styled Odoo link for final user confirmation.
• Advanced Context Extraction: Documentation on how the agent identifies titles, durations, and descriptions from conversational context.
• Observability: Integrated details on the Logfire spans used to trace date validation, LLM queries, and MCP tool executions.

Reasoning Transparency

The documentation covers the unique steps for the calendar flow:

1. : Contextual analysis.
2. : Temporal logic processing.
3. : Real-time past-date validation.
4. : Odoo server interaction via MCP.

This addition completes the documentation for the core administrative agents in the Perry ecosystem.