IB-WP-0019-T06: workspace budget CLI

infospace-bench budget list <workspace> walks <workspace>/infospaces/*
and prints one row per infospace with slug, plans_count, runs_count,
total_tokens, total_cost_usd_known, total_cost_usd_estimated,
last_run_at, and latest_snapshot_id. infospace-bench budget show
<root> dumps the full plans/usage/summary structure for a single
infospace.

Missing budget directories are treated as zero rows rather than errors,
so the CLI is safe to run on partially-populated or fresh workspaces.

120 tests pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/infospace_bench/budget.py

@@ -375,6 +375,75 @@ def _post_json(url: str, payload: dict[str, Any], timeout: float) -> None:
         response.read()
 
 
+def budget_show(root: str | Path) -> dict[str, Any]:
+    """Return the full per-infospace budget structure for inspection."""
+    root_path = Path(root)
+    plans_payload = _read_plans(root_path / PLANS_FILE)
+    usage_payload = _read_usage(root_path / USAGE_FILE)
+    variance = read_run_variance(root_path)
+    return {
+        "root": str(root_path),
+        "plans": {
+            "schema_version": plans_payload.get("schema_version"),
+            "pruned_count": plans_payload.get("pruned_count") or 0,
+            "snapshots": list(plans_payload.get("snapshots") or []),
+        },
+        "usage": {
+            "schema_version": usage_payload.get("schema_version"),
+            "runs": list(usage_payload.get("runs") or []),
+        },
+        "summary": variance,
+    }
+
+
+def budget_list_workspace(workspace: str | Path) -> list[dict[str, Any]]:
+    """Walk ``<workspace>/infospaces/*/output/budget/`` and roll up each infospace.
+
+    Missing budget directories are treated as zero, not as errors. Returns a
+    list of summaries in slug order.
+    """
+    workspace_path = Path(workspace)
+    infospaces_dir = workspace_path / "infospaces"
+    if not infospaces_dir.is_dir():
+        return []
+    rollups: list[dict[str, Any]] = []
+    for entry in sorted(infospaces_dir.iterdir()):
+        if not entry.is_dir():
+            continue
+        rollups.append(_summarise_infospace(entry))
+    return rollups
+
+
+def _summarise_infospace(root: Path) -> dict[str, Any]:
+    plans = read_plan_snapshots(root)
+    runs = read_usage_runs(root)
+    total_tokens = 0
+    total_cost_known = 0.0
+    total_cost_estimated = 0.0
+    last_run_at: str | None = None
+    for run in runs:
+        rollup = run.get("rollup") or {}
+        total_tokens += int(rollup.get("total_tokens") or 0)
+        total_cost_known += _coerce_float(rollup.get("total_cost_usd_known")) or 0.0
+        estimated = _coerce_float(rollup.get("total_cost_usd_estimated"))
+        if estimated is not None:
+            total_cost_estimated += estimated
+        completed_at = run.get("completed_at")
+        if isinstance(completed_at, str) and (last_run_at is None or completed_at > last_run_at):
+            last_run_at = completed_at
+    return {
+        "slug": root.name,
+        "root": str(root),
+        "plans_count": len(plans),
+        "runs_count": len(runs),
+        "total_tokens": total_tokens,
+        "total_cost_usd_known": round(total_cost_known, 6),
+        "total_cost_usd_estimated": round(total_cost_estimated, 6) if total_cost_estimated else None,
+        "last_run_at": last_run_at,
+        "latest_snapshot_id": plans[-1].get("snapshot_id") if plans else None,
+    }
+
+
 def read_run_variance(root: str | Path) -> dict[str, Any] | None:
     path = Path(root) / SUMMARY_FILE
     if not path.is_file():