Investigate active company IDs in context

[marcfargas]

Summary

Investigate how Odoo's multi-company context works and how to properly handle allowed_company_ids in the client.

Background

Odoo uses allowed_company_ids in the context to determine the active companies for the current session. Important distinction:

• allowed_company_ids = companies the user wants to see (selected in UI)
• NOT the same as companies the user can access (which may be more)

The variable name is misleading - it's more like "active_company_ids" or "selected_company_ids".

This affects:

• Which records are shown by default
• Default company for new records
• Which company's settings/sequences apply

Questions to investigate

1. How does allowed_company_ids filter results in search and searchRead?
2. How to determine which companies the user actually has access to?
3. How to switch active companies mid-session via API?
4. What's the relationship with company_id vs company_ids fields on records?

Acceptance criteria

• Document the behavior in a new skill file (base/multi-company.md)
• Add examples for common multi-company patterns
• Consider if client needs a setActiveCompanies() helper

🤖 Identified by Pi (pi-mono)