Add template cProfile runner

.gitignore

@@ -2,7 +2,8 @@ __pycache__/
 logger/
 dataset/
 data/
+profiling/results/
 #Ignore vscode AI rules
 .*/
 .*
-!.env.example
+!.env.example

profiling/README.md

@@ -0,0 +1,15 @@
+# Template profiling
+
+Profile a template from the repository root:
+
+```bash
+python profiling/profile_template.py <template>
+```
+
+The command runs the template with Python's built-in `cProfile` and writes the
+binary profile plus a cumulative-time report to
+`profiling/results/<template>/`.
+
+Install the template's dependencies first. For long-running templates, reduce
+the workload in its `fenn.yaml` before profiling and restore it afterwards.
+Generated profiles are environment-specific and are not committed.

profiling/profile_template.py

@@ -0,0 +1,50 @@
+import argparse
+import pstats
+import subprocess
+import sys
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description="Profile a fenn template.")
+    parser.add_argument("template", help="Template directory to profile")
+    parser.add_argument("--limit", type=int, default=25, help="Rows in the report")
+    args = parser.parse_args()
+
+    template = ROOT / args.template
+    entrypoint = template / "main.py"
+    if not entrypoint.is_file() or template.parent != ROOT:
+        parser.error(f"unknown template: {args.template}")
+
+    output_dir = ROOT / "profiling" / "results" / args.template
+    output_dir.mkdir(parents=True, exist_ok=True)
+    profile_path = output_dir / "cprofile.prof"
+    report_path = output_dir / "cprofile.txt"
+
+    subprocess.run(
+        [
+            sys.executable,
+            "-m",
+            "cProfile",
+            "-o",
+            str(profile_path),
+            entrypoint.name,
+        ],
+        cwd=template,
+        check=True,
+    )
+
+    with report_path.open("w", encoding="utf-8") as report:
+        pstats.Stats(str(profile_path), stream=report).strip_dirs().sort_stats(
+            "cumulative"
+        ).print_stats(args.limit)
+
+    print(f"Profile: {profile_path}")
+    print(f"Report:  {report_path}")
+
+
+if __name__ == "__main__":
+    main()