Bidding System for Job Postings (Similar to Freelancer Platforms)

I would like to request the addition of a bidding system for job postings within the plugin. Similar to how platforms like Freelancer operate, this feature would allow users to post jobs or projects, and other users can submit bids for those jobs. This would be useful for websites that connect employers and freelancers.

Key Features:

Job Posting: Users can create detailed job postings, specifying project requirements, deadlines, and budget.
Bidding Mechanism: Other users can submit bids, proposing their price and timeline to complete the job.
Bid Management: Employers can view all bids, sort/filter them, and select the most suitable bid.
Communication: A messaging system between the job poster and bidders to discuss project details.
Awarding the Job: Once a bid is selected, the job is awarded to that bidder, with options for both parties to confirm the project start.
Use Case: This feature would allow websites powered by this plugin to operate similarly to freelance marketplaces, enabling seamless project matching between job posters and service providers.

The issue does not name any files, tests, or entry points. Begin by mapping the plugin's existing job-posting, user, and messaging flows, then define the scope and design for posting requirements, bidding, selection, awarding, and communication before implementation. Done would require agreed behavior and coverage for the complete workflow.

Written by the indexing model from the issue text.