feat: add profiled agent challenge harness

examples/agent_challenges/prompts.py

@@ -0,0 +1,72 @@
+from __future__ import annotations
+
+import hashlib
+import re
+from dataclasses import dataclass
+from pathlib import Path
+
+from .models import InstructionProfile, LoadedChallenge
+
+_PROMPT_DIR = Path(__file__).resolve().parent
+_BASE_PROMPT = _PROMPT_DIR / "base-prompt.md"
+_PROFILE_DIR = _PROMPT_DIR / "profile-prompts"
+
+_PLACEHOLDER_RE = re.compile(r"\{\{(\w+)\}\}")
+
+
+def _sha256(text: str) -> str:
+    return hashlib.sha256(text.encode("utf-8")).hexdigest()
+
+
+@dataclass(frozen=True, slots=True)
+class RenderedPrompt:
+    text: str
+    base_sha256: str
+    profile_sha256: str
+    challenge_sha256: str
+    rendered_sha256: str
+
+
+def _load_profile_fragment(profile: InstructionProfile) -> str:
+    path = _PROFILE_DIR / f"{profile.value}.md"
+    return path.read_text(encoding="utf-8")
+
+
+def _resolve_placeholders(template: str, *, variables: dict[str, str]) -> str:
+    def _replace(match: re.Match[str]) -> str:
+        key = match.group(1)
+        if key not in variables:
+            raise ValueError(f"unresolved placeholder {{{{{key}}}}}")
+        return variables[key]
+
+    return _PLACEHOLDER_RE.sub(_replace, template)
+
+
+def compose_trial_prompt(
+    challenge: LoadedChallenge,
+    *,
+    profile: InstructionProfile,
+    wf_command_prefix: str,
+    server_context: str,
+    workspace_path: Path,
+) -> RenderedPrompt:
+    base_text = _BASE_PROMPT.read_text(encoding="utf-8")
+    profile_text = _load_profile_fragment(profile)
+    challenge_text = challenge.prompt_path.read_text(encoding="utf-8")
+
+    rendered = _resolve_placeholders(
+        base_text,
+        variables={
+            "wf_command_prefix": wf_command_prefix,
+            "server_context": server_context,
+            "workspace_path": str(workspace_path),
+        },
+    )
+
+    return RenderedPrompt(
+        text=f"{rendered}\n{profile_text}\n{challenge_text}",
+        base_sha256=_sha256(base_text),
+        profile_sha256=_sha256(profile_text),
+        challenge_sha256=_sha256(challenge_text),
+        rendered_sha256=_sha256(f"{rendered}\n{profile_text}\n{challenge_text}"),
+    )