Add one-way Odoo contact sync script (Option B)

[classicitbb]

Motivation

• Provide a simple "Option B" one-way sync to propagate contact changes from a primary Odoo DB to multiple target Odoo DBs.
• Attempt to deduplicate records using a shared x_global_uuid custom field and fall back to normalized email/phone matching.
• Surface ambiguous matches as conflicts so they can be resolved manually.
• Maintain progress with a state file so only recent changes are synced.

Description

• Add sync_contacts.py which implements an XML-RPC OdooClient, ensures the x_global_uuid field exists, fetches recent contacts, finds matches, and creates/updates targets via create/write calls.
• Implement matching and conflict logic in functions such as find_match, prepare_payload, sync_contact, and the top-level sync_contacts.
• Add config.example.yaml with primary, targets, and sync settings and a requirements.txt that pins PyYAML==6.0.2 for configuration parsing.
• Add README.md documenting setup, usage (python sync_contacts.py --config config.yaml --state state.json), and notes about conflicts.log and state.json.

Testing

• No automated tests are included in this change.
• No automated tests were executed as part of this rollout because none were provided.
• Basic repository operations (adding and committing the new files) completed successfully.
• Runtime or integration validation against Odoo instances was not performed by automated tests.

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Codex Task