feat: integrate Arena with Skill marketplace (search before + publish after)

src/epochx/core/prompt_generator.py

@@ -7,23 +7,59 @@
 from epochx.core.task import OutputType, Task, WorkspaceInfo
 
 
+def _skill_name(task: Task) -> str:
+    """Generate a skill name from benchmark + task external_id.
+
+    e.g. "swebench-verified-django-11099"
+    """
+    parts = task.external_id.replace("__", "-").replace("_", "-").lower()
+    return f"{task.benchmark}-{parts}"
+
+
 def generate_prompt(task: Task, ws_info: WorkspaceInfo) -> str:
     """Generate a standardized markdown prompt for an agent.
 
     Sections:
     - Task ID
+    - Before You Start (search for existing skills)
     - Instructions
     - Workspace path
     - Environment Commands (SSH if docker, direct if host)
     - Available Tools
     - Output instructions (based on OutputType)
+    - After Completion (distill & publish skill)
     - When Done
     """
     sections: list[str] = []
 
+    skill_name = _skill_name(task)
+
     # Header
     sections.append(f"# Task: {task.id}\n")
 
+    # Before You Start — search for skills
+    sections.append("## Before You Start\n")
+    sections.append(
+        "Search the EpochX skill marketplace for existing solutions or strategies "
+        "that might help with this task:\n"
+    )
+    sections.append("```bash")
+    sections.append(f"epochx skill search \"{task.benchmark} {task.external_id}\"")
+    sections.append("```\n")
+    sections.append(
+        "If relevant skills are found (score > 0.3), download and review them — "
+        "especially the `references/` directory which may contain trajectories "
+        "from previous successful attempts:\n"
+    )
+    sections.append("```bash")
+    sections.append("epochx skill use <skill_id> --out ./skill-ref")
+    sections.append("```\n")
+    sections.append(
+        "Use any helpful patterns, but solve the task independently. "
+        "Do not blindly copy solutions."
+    )
+    sections.append("")
+
     # Instructions
     sections.append("## Instructions\n")
     sections.append(task.prompt)
@@ -91,13 +127,80 @@ def generate_prompt(task: Task, ws_info: WorkspaceInfo) -> str:
         )
     sections.append("")
 
+    # Trajectory
+    sections.append("## Trajectory (optional)\n")
+    sections.append(
+        "Your SSH commands are logged automatically. "
+        "For richer trajectory data (reasoning, tool choices), "
+        "append JSONL to `/.epochx/trajectory.jsonl` inside the container:\n"
+    )
+    sections.append("```json")
+    sections.append('{"step":1,"type":"thought","content":"analyzing the issue..."}')
+    sections.append('{"step":2,"type":"tool_call","tool_name":"grep","tool_input":"grep -r pattern .","tool_output":"..."}')
+    sections.append("```")
+    sections.append("")
+
+    # After Completion — distill skill
+    sections.append("## After Completion — Publish Skill\n")
+    sections.append(
+        "After solving the task, distill your approach into a reusable skill "
+        "so future agents can learn from your experience.\n"
+    )
+    sections.append(
+        "**Step 1.** Create the skill directory in the workspace:\n"
+    )
+    sections.append("```bash")
+    sections.append(f"mkdir -p {ws_info.path}/skill/references")
+    sections.append("```\n")
+    sections.append(
+        "**Step 2.** Write a SKILL.md summarizing your approach:\n"
+    )
+    sections.append("```bash")
+    sections.append(f"cat > {ws_info.path}/skill/SKILL.md << 'SKILLEOF'")
+    sections.append(f"# {skill_name}\n")
+    sections.append(f"## Task\n{task.benchmark} / {task.external_id}\n")
+    sections.append("## Approach\n(Describe your strategy: what you looked at, "
+                     "what the root cause was, how you fixed it)\n")
+    sections.append("## Key Insight\n(One-line takeaway that helps future agents)\n")
+    sections.append("## Files Changed\n(List the files you modified and why)")
+    sections.append("SKILLEOF")
+    sections.append("```\n")
+    sections.append(
+        "**Step 3.** Copy the trajectory (auto-recorded) into the skill:\n"
+    )
+    sections.append("```bash")
+    epochx_dir = f"{ws_info.path}/.epochx"
+    sections.append(
+        f"cp {epochx_dir}/trajectory_collected.json "
+        f"{ws_info.path}/skill/references/trajectory.json 2>/dev/null || true"
+    )
+    sections.append(
+        f"cp {epochx_dir}/output.txt "
+        f"{ws_info.path}/skill/references/output.txt 2>/dev/null || true"
+    )
+    sections.append("```\n")
+    sections.append(
+        "**Step 4.** Publish the skill to EpochX:\n"
+    )
+    sections.append("```bash")
+    sections.append(
+        f"epochx skill submit --name \"{skill_name}\" "
+        f"--dir {ws_info.path}/skill"
+    )
+    sections.append("```")
+    sections.append("")
+
     # When Done
     sections.append("## When Done\n")
     sections.append(
-        f"Run the following command to collect your output:\n"
+        f"Run these commands in order:\n"
     )
-    sections.append(f"```bash")
+    sections.append("```bash")
+    sections.append(f"# 1. Collect your solution output")
     sections.append(f"epochx-bench collect {task.id}")
+    sections.append(f"")
+    sections.append(f"# 2. Then publish skill (after collect, so trajectory is available)")
+    sections.append(f"# Follow the 'After Completion' steps above")
     sections.append(f"```")
 
     return "\n".join(sections)