feat: enhance agent and board APIs with role-based tags and improved documentation

backend/tests/test_template_size_budget.py

@@ -0,0 +1,23 @@
+# ruff: noqa: S101
+"""Template size guardrails for injected heartbeat context."""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+HEARTBEAT_CONTEXT_LIMIT = 20_000
+TEMPLATES_DIR = Path(__file__).resolve().parents[1] / "templates"
+
+
+def test_heartbeat_templates_fit_in_injected_context_limit() -> None:
+    """Heartbeat templates must stay under gateway injected-context truncation limit."""
+    targets = (
+        "HEARTBEAT_LEAD.md",
+        "HEARTBEAT_AGENT.md",
+        "MAIN_HEARTBEAT.md",
+    )
+    for name in targets:
+        size = (TEMPLATES_DIR / name).stat().st_size
+        assert size <= HEARTBEAT_CONTEXT_LIMIT, (
+            f"{name} is {size} chars (limit {HEARTBEAT_CONTEXT_LIMIT})"
+        )