agents: project .opencode/agents/ ignored; global agents leak across projects

Summary

Two agent discovery regressions in v2:

1. Project-level .opencode/agents/ directory is ignored — file-based agents not discovered
2. Global ~/.config/opencode/agents/ agents leak across all projects — no project scoping

Environment

• opencode version: 2.0.10
• OS: Linux 6.18.33.2-microsoft-standard-WSL2 (WSL2 Ubuntu)
• Terminal: xterm-256color (truecolor)
• Shell: /usr/bin/zsh
• Install/channel: latest (curl installer)
• Active plugins: ./.opencode/plugins/observer.cjs (local)

Reproduction

Bug 1: Project .opencode/agents/ ignored

1. Create a project with .opencode/agents/content-agent.md:

   ---
   id: content-agent
   name: Content Agent
   model: openrouter/nvidia/nemotron-3-ultra-550b-a55b:free
   mode: primary
   ---
   System prompt here...
   

2. Start OpenCode in that project (opencode --standalone)
3. Run opencode debug agents
4. Observe: content-agent NOT in list — only built-ins (build, explore, general, plan, summary, title, compaction)

Bug 2: Global agents leak across projects

1. Place agent files in ~/.config/opencode/agents/*.md (with proper frontmatter)
2. Start OpenCode in Project A → agents appear in debug agents
3. Start OpenCode in Project B (different directory, no agents) → same agents appear
4. Set default_agent: "content-agent" in Project B config → picks up Project A's agent

Expected Behavior

• Bug 1: Project .opencode/agents/ should be discovered automatically (v1 behavior worked)
• Bug 2: Global agents should be namespaced or project config should isolate agent scope. Project-specific default_agent should not resolve to another project's agents.

Actual Behavior

• Project file-based agents completely ignored
• Global agents are truly global — visible and usable in every project
• Workaround: Define agents in project config agents object (JSON) — works but duplicates prompt from .md files

Additional Context

• This worked in v1. Project .opencode/agents/ (or agent/, mode/) were discovered
• Migration guide says: "V2 discovers all four directories" and "V2 translates legacy agent frontmatter automatically"
• File-based discovery from global config dir works, but creates cross-project leakage
• Project config agents object (JSON) works correctly for project scoping
• Source agent .md files preserved in .opencode/agents/ with id, name, model, mode, color, description frontmatter
• Config: /mnt/share/TwoTimesTwo/opencode.jsonc has default_agent: "content-agent" and agents object with 6 agents (content-agent, daily-agent, deploy-agent, infra-agent, research-agent, visual-agent)
• Each agent in config has // Source: .opencode/agents/<name>.md comment linking to source file

Start with the agent discovery path exercised by opencode debug agents, comparing project .opencode/agents/ with the global ~/.config/opencode/agents/ directory and project agents configuration. Trace how default_agent resolves across projects; done means project Markdown agents are discovered and global agents do not leak into unrelated projects, with the documented reproduction cases covered.