Issue #006: Write & Broadcast Operations

[fbbp]

Description

Implement operations for member-to-member communication: write (direct message) and broadcast (team-wide message).

Acceptance Criteria

• write validates recipient exists and is active
• write creates message in recipient's inbox
• broadcast creates messages in all team members' inboxes
• Messages include sender, content, timestamp
• Invalid recipients return descriptive errors
• Sender identity is verified

Sub-issues

• #6.1 Implement write operation
• #6.2 Implement broadcast operation

Dependencies

• Blocked by: Odoo 15 adaptation #4, docs: small contribution #5

Priority

P0

[affaan-m]

See discussion in #122 - these issues appear to be for a separate TeammateTool project.

[affaan-m]

Closing: This is a feature request for a separate TeammateTool project, not a bug/feature for ECC. Please create these issues in your own repository. Feel free to reference ECC patterns!