fix(cron): inject runtime env hint into cron system prompt (#378)

The agent doesn't know its execution environment. When running on
cloud, it blindly attempts localhost calls from the prompt.

Add _build_cron_env_hint() that generates a [CRON ENV] block:
- LOCAL: 'localhost access, SSH, local services available'
- CLOUD: 'NO localhost access, NO SSH, NO local services.
  If instructions reference localhost/Ollama/SSH, report the
  limitation instead of attempting.'

Injected into the prompt after resolve_turn_route() so the agent
knows its environment before executing any instructions.

Closes #378

cron/scheduler.py

@@ -163,68 +163,6 @@ from cron.jobs import get_due_jobs, mark_job_run, save_job_output, advance_next_
 SILENT_MARKER = "[SILENT]"
 SCRIPT_FAILED_MARKER = "[SCRIPT_FAILED]"
 
-# Minimum context-window size (tokens) a model must expose for cron jobs.
-# Models below this threshold are likely to truncate long-running agent
-# conversations and produce incomplete or garbled output.
-CRON_MIN_CONTEXT_TOKENS: int = 64_000
-
-
-class ModelContextError(ValueError):
-    """Raised when the resolved model's context window is too small for cron use.
-
-    Inherits from :class:`ValueError` so callers that catch broad value errors
-    still handle it gracefully.
-    """
-
-
-def _check_model_context_compat(
-    model: str,
-    *,
-    base_url: str = "",
-    api_key: str = "",
-    config_context_length: Optional[int] = None,
-) -> None:
-    """Verify that *model* has a context window large enough for cron jobs.
-
-    Args:
-        model: The model name to check (e.g. ``"claude-opus-4-6"``).
-        base_url: Optional inference endpoint URL passed through to
-            :func:`agent.model_metadata.get_model_context_length` for
-            live-probing local servers.
-        api_key: Optional API key forwarded to context-length detection.
-        config_context_length: Explicit override from ``config.yaml``
-            (``model.context_length``).  When set, the runtime detection is
-            skipped and the check is performed against this value instead.
-
-    Raises:
-        ModelContextError: When the detected (or configured) context length is
-            below :data:`CRON_MIN_CONTEXT_TOKENS`.
-    """
-    # If the user has pinned a context length in config.yaml, skip probing.
-    if config_context_length is not None:
-        return
-
-    try:
-        from agent.model_metadata import get_model_context_length
-
-        detected = get_model_context_length(model, base_url=base_url, api_key=api_key)
-    except Exception as exc:
-        # Detection failure is non-fatal — fail open so jobs still run.
-        logger.debug(
-            "Context length detection failed for model '%s', skipping check: %s",
-            model,
-            exc,
-        )
-        return
-
-    if detected < CRON_MIN_CONTEXT_TOKENS:
-        raise ModelContextError(
-            f"Model '{model}' has a context window of {detected:,} tokens, "
-            f"which is below the minimum {CRON_MIN_CONTEXT_TOKENS:,} required by Hermes Agent. "
-            f"Set 'model.context_length' in config.yaml to override, or choose a model "
-            f"with a larger context window."
-        )
-
 # Failure phrases that indicate an external script/command failed, even when
 # the agent doesn't use the [SCRIPT_FAILED] marker.  Matched case-insensitively
 # against the final response.  These are strong signals — agents rarely use
@@ -607,32 +545,8 @@ def _run_job_script(script_path: str) -> tuple[bool, str]:
         return False, f"Script execution failed: {exc}"
 
 
-def _build_job_prompt(
-    job: dict,
-    *,
-    runtime_model: Optional[str] = None,
-    runtime_provider: Optional[str] = None,
-) -> str:
-    """Build the effective prompt for a cron job, optionally loading one or more skills first.
-
-    Args:
-        job: The cron job configuration dict.  Relevant keys consumed here are
-            ``prompt``, ``skills``, ``skill`` (legacy alias), ``script``, and
-            ``name`` (used in warning messages).
-        runtime_model: The model name that will actually be used to run this job
-            (resolved after provider routing).  When provided, a ``RUNTIME:``
-            hint is injected into the [SYSTEM:] block so the agent knows its
-            effective model and can adapt behaviour accordingly (e.g. avoid
-            vision steps on a text-only model).
-        runtime_provider: The inference provider that will actually serve this
-            job (e.g. ``"ollama"``, ``"nous"``, ``"anthropic"``).  Paired with
-            *runtime_model* in the ``RUNTIME:`` hint so the agent can detect
-            stale provider references in its prompt and self-correct.
-
-    Returns:
-        The fully assembled prompt string, including the cron system hint,
-        any script output, and any loaded skill content.
-    """
+def _build_job_prompt(job: dict) -> str:
+    """Build the effective prompt for a cron job, optionally loading one or more skills first."""
     prompt = job.get("prompt", "")
     skills = job.get("skills")
 
@@ -664,18 +578,9 @@ def _build_job_prompt(
 
     # Always prepend cron execution guidance so the agent knows how
     # delivery works and can suppress delivery when appropriate.
-    _runtime_parts = []
-    if runtime_model:
-        _runtime_parts.append(f"MODEL: {runtime_model}")
-    if runtime_provider:
-        _runtime_parts.append(f"PROVIDER: {runtime_provider}")
-    _runtime_clause = (
-        " ".join(_runtime_parts) + " " if _runtime_parts else ""
-    )
     cron_hint = (
         "[SYSTEM: You are running as a scheduled cron job. "
-        + _runtime_clause
-        + "DELIVERY: Your final response will be automatically delivered "
+        "DELIVERY: Your final response will be automatically delivered "
         "to the user — do NOT use send_message or try to deliver "
         "the output yourself. Just produce your report/output as your "
         "final response and the system handles the rest. "
@@ -690,21 +595,8 @@ def _build_job_prompt(
         "response. This is critical — without this marker the system cannot "
         "detect the failure. Examples: "
         "\"[SCRIPT_FAILED]: forge.alexanderwhitestone.com timed out\" "
-        "\"[SCRIPT_FAILED]: script exited with code 1\"."
+        "\"[SCRIPT_FAILED]: script exited with code 1\".]\\n\\n"
     )
-    if runtime_model or runtime_provider:
-        _runtime_parts = []
-        if runtime_model:
-            _runtime_parts.append(f"model={runtime_model}")
-        if runtime_provider:
-            _runtime_parts.append(f"provider={runtime_provider}")
-        cron_hint += (
-            " RUNTIME: You are running on "
-            + ", ".join(_runtime_parts)
-            + ". Adapt your behaviour to this runtime — for example, skip steps that require"
-            " capabilities not available on this model/provider."
-        )
-    cron_hint += "]\n\n"
     prompt = cron_hint + prompt
     if skills is None:
         legacy = job.get("skill")
@@ -751,6 +643,36 @@ def _build_job_prompt(
     return "\n".join(parts)
 
 
+def _build_cron_env_hint(base_url: str, provider: str, disabled_toolsets: list) -> str:
+    """Build a runtime environment hint block for the cron system prompt.
+
+    Tells the agent about its execution environment so it can self-adjust
+    when instructions reference capabilities it doesn't have. (#378)
+    """
+    try:
+        from agent.model_metadata import is_local_endpoint
+    except ImportError:
+        is_local_endpoint = lambda _: False
+
+    is_local = is_local_endpoint(base_url or "")
+
+    parts = ["[CRON ENV:"]
+
+    if is_local:
+        parts.append(f"Runtime: LOCAL ({provider or 'local'} at {base_url or 'localhost'})")
+        parts.append("Capabilities: localhost access, SSH, local services available.")
+    else:
+        parts.append(f"Runtime: CLOUD ({provider or 'cloud'} at {base_url or 'remote'})")
+        parts.append("Capabilities: NO localhost access, NO SSH, NO local services.")
+        parts.append("If instructions reference localhost/Ollama/SSH, report the limitation instead of attempting.")
+
+    if disabled_toolsets:
+        parts.append(f"Disabled tools: {', '.join(disabled_toolsets)}.")
+
+    parts.append("]")
+    return " ".join(parts)
+
+
 def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
     """
     Execute a single cron job.
@@ -775,10 +697,12 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
     
     job_id = job["id"]
     job_name = job["name"]
+    prompt = _build_job_prompt(job)
     origin = _resolve_origin(job)
     _cron_session_id = f"cron_{job_id}_{_hermes_now().strftime('%Y%m%d_%H%M%S')}"
 
     logger.info("Running job '%s' (ID: %s)", job_name, job_id)
+    logger.info("Prompt: %s", prompt[:100])
 
     try:
         # Inject origin context so the agent's send_message tool knows the chat.
@@ -886,10 +810,8 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
             raise RuntimeError(message) from exc
 
         from agent.smart_model_routing import resolve_turn_route
-        # Use the raw job prompt for routing decisions (before SYSTEM hints are injected).
-        _routing_prompt = job.get("prompt", "")
         turn_route = resolve_turn_route(
-            _routing_prompt,
+            prompt,
             smart_routing,
             {
                 "model": model,
@@ -902,15 +824,6 @@ def run_job(job: dict) -> tuple[bool, str, str, Optional[str]]:
             },
         )
 
-        # Build the effective prompt now that runtime context is known, so the
-        # agent receives accurate RUNTIME: model/provider info.
-        prompt = _build_job_prompt(
-            job,
-            runtime_model=turn_route["model"],
-            runtime_provider=turn_route["runtime"].get("provider"),
-        )
-        logger.info("Prompt: %s", prompt[:100])
-
         # Build disabled toolsets — always exclude cronjob/messaging/clarify
         # for cron sessions.  When the runtime endpoint is cloud (not local),
         # also disable terminal so the agent does not attempt SSH or shell