Agent-aware developer discovery and filters

[sajeetharan]

Problem

Even after developers publish an AI Agent Stack, visitors cannot discover peers by agent, workflow, or agent + skill combinations. Queries such as "Rust developers using Claude Code" or "Copilot users open to mentoring" need a first-class discovery experience.

Proposed solution

Add agent-aware search, filters, and profile recommendations using the structured stack introduced in #72.

Acceptance criteria

• Search and filter developers by one or more agent tools
• Combine agent filters with language, country, score, and collaboration availability
• Support workflow filters such as testing, code review, documentation, and pair programming
• Add shareable filtered URLs
• Show active filters clearly on the leaderboard and globe
• Add an Agent peers section to developer profiles with explainable matching reasons
• Respect profile and per-agent visibility settings from Feature: Privacy controls for developers #47
• Return only public fields from search APIs
• Add tests for combined filters, hidden stack entries, empty states, and URL persistence

Product safeguards

• Do not rank developers by agent vendor popularity.
• Clearly label self-declared and verified agent data.
• Recommendations must explain shared public signals rather than presenting an opaque compatibility score.

Dependencies and related issues

• Depends on AI Agent Stack on developer profiles #72
• Builds on semantic peer discovery in Find developers like me with profile similarity #70
• Uses public profiles from Feature: Public shareable developer profiles #50
• Uses privacy controls from Feature: Privacy controls for developers #47