docs: implement Perry Human-in-the-Loop (HITL) technical documentation

[D3n3bX]

Description

This PR introduces the technical documentation for the Perry HITL module (perry.pending.action). This module is the cornerstone of Perry's security architecture, ensuring all AI intents undergo human verification before execution.

Fixes #16

Key Technical Implementations

• Staging Architecture: Documented how AI payloads are stored in JSON and rendered into human-readable HTML tables via computed fields.
• Multi-Module Execution: Detailed the specific logic for automated creation of CRM Leads, Account Payments, and Calendar Events.
• Lookup & Validation Logic: Explained the fuzzy-search strategy for finding Partners/Journals and the automated posting of accounting entries.
• UTC Normalization: Documented the timezone handling for the Calendar integration.
• End-to-End Tracing: Integrated Logfire instrumentation details for auditing the transition from AI suggestion to Human confirmation.

This safety layer prevents 'Administrative Noise' by allowing users to quickly verify and commit AI-prepared tasks with a single click.