Add input_cost_trend / input_cost_series MCP tools (EIA diesel)

Real input price + WoW/YoY change + seasonal for diesel ($/gal). Formatters now
handle the item/label payload shape. Changelog updated.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ag_bids_mcp/format.py

@@ -130,14 +130,16 @@ _MONTH_NAMES_3 = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
 
 
 def fmt_price_trend(payload: dict, label: str = "price received") -> str:
-    commodity = payload.get("commodity")
+    name = payload.get("commodity") or payload.get("item")
     geo = payload.get("geo")
+    label = payload.get("label") or label
     unit = payload.get("unit") or "$/bu"
     t = payload.get("trend")
+    loc = f" — {geo}" if geo else ""
     if not t:
-        return f"### {commodity} — {geo} — {label}\n\nNo data on file.\n"
+        return f"### {name}{loc} — {label}\n\nNo data on file.\n"
     when = _ym(t["period"])
-    lines = [f"### {commodity} — {geo} — {label}, {when}: {_unit_money(t['value_cents'], unit)}", ""]
+    lines = [f"### {name}{loc} — {label}, {when}: {_unit_money(t['value_cents'], unit)}", ""]
     arrow = _delta_arrow(t.get("change_cents"))
     lines.append(f"- **Change:** {arrow} {_signed(t.get('change_cents'))} ({_pct(t.get('change_pct'))}) vs prior period")
     if t.get("yoy_cents") is not None:
@@ -155,14 +157,15 @@ def fmt_price_trend(payload: dict, label: str = "price received") -> str:
 
 
 def fmt_price_series(payload: dict, max_points: int = 60) -> str:
-    commodity = payload.get("commodity")
+    name = payload.get("commodity") or payload.get("item")
     geo = payload.get("geo")
     unit = payload.get("unit") or "$/bu"
     series = payload.get("series") or []
+    loc = f" — {geo}" if geo else ""
     if not series:
-        return f"### {commodity} — {geo} series\n\nNo data on file.\n"
+        return f"### {name}{loc} series\n\nNo data on file.\n"
     shown = series[-max_points:]
-    head = [f"### {commodity} — {geo} — {payload.get('count', len(series))} periods "
+    head = [f"### {name}{loc} — {payload.get('count', len(series))} periods "
             f"(showing last {len(shown)})", "",
             "| Period | Price |", "|---|---:|"]
     body = [f"| {_ym(p['period'])} | {_unit_money(p['value_cents'], unit)} |" for p in shown]