fix: improve opencode trial resume controls

examples/agent_challenges/base-prompt.md

@@ -12,8 +12,9 @@ Use this command prefix:
 {{server_context}}
 
 Your writable trial workspace is `{{workspace_path}}`. Write attempt files only
-inside it. End with the challenge's requested YAML self-report. The self-report
-will be checked against observed tool calls and manually audited.
+inside it. End with the challenge's requested YAML self-report inline in your
+final answer. A run without an inline self-report is invalid. The inline
+self-report will be checked against observed tool calls and manually audited.
 
 Do not read files under other `workspaces/*` trial directories. Prior trial
 workspaces may contain complete answers. If you do read another trial workspace,

examples/agent_challenges/opencode_resume.py

@@ -3,7 +3,9 @@ from __future__ import annotations
 import json
 import subprocess
 from pathlib import Path
-from typing import Any
+from typing import Any, Literal
+
+PromptMode = Literal["auto", "continue", "final-report"]
 
 FINAL_REPORT_PROMPT = (
     "Your workflow attempt is over. Do not continue coding. Return only the "
@@ -62,6 +64,15 @@ def resume_prompt_for_result(result: dict[str, object]) -> str:
     return CONTINUE_PROMPT
 
 
+def resume_prompt_for_mode(result: dict[str, object], mode: PromptMode) -> str:
+    """Return the operator-selected resume prompt, falling back to auto detection."""
+    if mode == "continue":
+        return CONTINUE_PROMPT
+    if mode == "final-report":
+        return FINAL_REPORT_PROMPT
+    return resume_prompt_for_result(result)
+
+
 def build_resume_command(
     *,
     session_id: str,
@@ -77,6 +88,81 @@ def build_resume_command(
     return command
 
 
+def resume_command_from_result(
+    result: dict[str, Any],
+    *,
+    session_id: str | None = None,
+    attach_url: str | None = None,
+    model: str | None = None,
+    variant: str | None = None,
+    prompt_mode: PromptMode = "auto",
+) -> list[str]:
+    """Build a resume command from new metadata or recover it from old raw results."""
+    opencode = result.get("opencode")
+    if isinstance(opencode, dict):
+        command = opencode.get("resume_command")
+        has_override = (
+            any(value is not None for value in (session_id, attach_url, model, variant))
+            or prompt_mode != "auto"
+        )
+        if (
+            not has_override
+            and isinstance(command, list)
+            and all(isinstance(part, str) for part in command)
+        ):
+            return command
+
+    stdout = result.get("stdout")
+    stdout_text = stdout if isinstance(stdout, str) else ""
+    if isinstance(opencode, dict):
+        metadata_session_id = opencode.get("session_id")
+        metadata_model = opencode.get("model")
+        metadata_variant = opencode.get("variant")
+        metadata_attach_url = opencode.get("attach_url")
+    else:
+        metadata_session_id = None
+        metadata_model = None
+        metadata_variant = None
+        metadata_attach_url = None
+
+    recovered_session_id = (
+        session_id
+        or (metadata_session_id if isinstance(metadata_session_id, str) else None)
+        or extract_session_id(stdout_text)
+    )
+    if not recovered_session_id:
+        raise ValueError("result has no opencode session id; pass --session")
+
+    result_model = result.get("model")
+    result_variant = result.get("variant")
+    resolved_model = (
+        model
+        or (metadata_model if isinstance(metadata_model, str) else None)
+        or (result_model if isinstance(result_model, str) else None)
+    )
+    resolved_variant = (
+        variant
+        or (metadata_variant if isinstance(metadata_variant, str) else None)
+        or (result_variant if isinstance(result_variant, str) else None)
+    )
+    resolved_attach_url = attach_url or (
+        metadata_attach_url if isinstance(metadata_attach_url, str) else None
+    )
+
+    if not resolved_model:
+        raise ValueError("result has no opencode model; pass --model")
+    if not resolved_variant:
+        raise ValueError("result has no opencode variant; pass --variant")
+
+    return build_resume_command(
+        session_id=recovered_session_id,
+        attach_url=resolved_attach_url,
+        model=resolved_model,
+        variant=resolved_variant,
+        prompt=resume_prompt_for_mode(result, prompt_mode),
+    )
+
+
 def display_resume_command(command: list[str]) -> str:
     """Render an argv list for copy-paste display without changing execution."""
     return subprocess.list2cmdline(command)

examples/agent_challenges/resume_trial.py

@@ -11,11 +11,18 @@ from pathlib import Path
 from typing import Any
 
 try:
-    from .opencode_resume import display_resume_command, resume_result_path
+    from .opencode_resume import (
+        PromptMode,
+        display_resume_command,
+        resume_command_from_result,
+        resume_result_path,
+    )
 except ImportError:
     sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
     from examples.agent_challenges.opencode_resume import (
+        PromptMode,
         display_resume_command,
+        resume_command_from_result,
         resume_result_path,
     )
 
@@ -30,16 +37,23 @@ def _utf8_subprocess_env() -> dict[str, str]:
     return env
 
 
-def _load_command(result: dict[str, Any]) -> list[str]:
-    opencode = result.get("opencode")
-    if not isinstance(opencode, dict):
-        raise ValueError("result has no opencode metadata")
-    command = opencode.get("resume_command")
-    if not isinstance(command, list) or not all(
-        isinstance(part, str) for part in command
-    ):
-        raise ValueError("result has no resume_command; session id may be missing")
-    return command
+def _load_command(
+    result: dict[str, Any],
+    *,
+    session_id: str | None = None,
+    attach_url: str | None = None,
+    model: str | None = None,
+    variant: str | None = None,
+    prompt_mode: PromptMode = "auto",
+) -> list[str]:
+    return resume_command_from_result(
+        result,
+        session_id=session_id,
+        attach_url=attach_url,
+        model=model,
+        variant=variant,
+        prompt_mode=prompt_mode,
+    )
 
 
 def _display_command(command: list[str]) -> str:
@@ -49,12 +63,24 @@ def _display_command(command: list[str]) -> str:
 def resume_from_result(
     result_path: Path,
     *,
+    session_id: str | None = None,
+    attach_url: str | None = None,
+    model: str | None = None,
+    variant: str | None = None,
+    prompt_mode: PromptMode = "auto",
     run_fn: RunFn = subprocess.run,
 ) -> Path:
     result = json.loads(result_path.read_text(encoding="utf-8"))
     if not isinstance(result, dict):
         raise ValueError("result file must contain a JSON object")
-    command = _load_command(result)
+    command = _load_command(
+        result,
+        session_id=session_id,
+        attach_url=attach_url,
+        model=model,
+        variant=variant,
+        prompt_mode=prompt_mode,
+    )
     workspace_path = result.get("workspace_path")
     cwd = str(workspace_path) if isinstance(workspace_path, str) else None
     started = time.monotonic()
@@ -89,6 +115,16 @@ def main(argv: list[str] | None = None) -> int:
         description="Print or run an OpenCode trial resume command."
     )
     parser.add_argument("--from-result", type=Path, required=True)
+    parser.add_argument("--session")
+    parser.add_argument("--attach", dest="attach_url")
+    parser.add_argument("--model")
+    parser.add_argument("--variant")
+    parser.add_argument(
+        "--prompt-mode",
+        choices=("auto", "continue", "final-report"),
+        default="auto",
+        help="Choose the resume prompt instead of relying on auto detection.",
+    )
     parser.add_argument("--print-command", action="store_true")
     parser.add_argument("--run", action="store_true")
     args = parser.parse_args(argv)
@@ -97,9 +133,25 @@ def main(argv: list[str] | None = None) -> int:
         result = json.loads(args.from_result.read_text(encoding="utf-8"))
         if not isinstance(result, dict):
             raise ValueError("result file must contain a JSON object")
-        command = _load_command(result)
+        command = _load_command(
+            result,
+            session_id=args.session,
+            attach_url=args.attach_url,
+            model=args.model,
+            variant=args.variant,
+            prompt_mode=args.prompt_mode,
+        )
         if args.run:
-            print(resume_from_result(args.from_result).as_posix())
+            print(
+                resume_from_result(
+                    args.from_result,
+                    session_id=args.session,
+                    attach_url=args.attach_url,
+                    model=args.model,
+                    variant=args.variant,
+                    prompt_mode=args.prompt_mode,
+                ).as_posix()
+            )
         else:
             print(_display_command(command))
     except ValueError as exc: