Initial commit: ag-bids MCP server

Exposes live + historical ag-bids commodity data (from the ag-monitor
service at agbids.paul.farm) as MCP tools, sitting behind MetaMCP at
https://mcp.jpaul.io/metamcp/ag-bids/mcp.

Pattern mirrors zerto-docs-rag with one addition: HTTP Basic auth in
front of the streamable-HTTP transport so namespace guessers can't reach
the tools. Stdio transport is unaffected (used by local Claude Desktop
dev).

Tools (markdown returns, ~15 LOC each):
  best_local_bid(commodity)       — where to sell corn/soy/wheat today,
                                    for the current calendar month only
  current_lime_price()            — latest lime quotes ($/ton)
  current_input_price(product?)   — MAP / Potash / Lime
  latest_prices(...)              — filtered snapshot
  price_history(...)              — per-(source,delivery) trend
  list_sources / list_commodities / list_deliveries
  source_health()                 — healthy / stale / down buckets
  todays_summary()                — same shape as morning brief snapshot

Data path: ag-bids-mcp -> X-API-Key -> /api/data/* on ag-monitor
(reuses BRIEF_API_KEY).

Tests: 24 covering the httpx client, markdown formatters, HTTP Basic
middleware (401/200), and JSONL usage logging.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.env.example

@@ -0,0 +1,21 @@
+# --- MCP transport ---
+# stdio for local Claude Desktop dev, streamable-http for the deployed container.
+MCP_TRANSPORT=streamable-http
+MCP_HOST=0.0.0.0
+MCP_PORT=8000
+
+# --- Upstream: ag-monitor (where the data actually lives) ---
+# Reuse the same key ag-monitor already issues for /api/brief/* — both clients
+# are internal-trusted, so a separate key is unnecessary friction.
+AG_BIDS_API_URL=https://agbids.paul.farm
+AG_BIDS_API_KEY=
+AG_BIDS_API_TIMEOUT_SECS=20
+
+# --- HTTP Basic auth (REQUIRED — server refuses to start without both) ---
+# These guard the MCP itself. MetaMCP injects them on every upstream call.
+AG_BIDS_MCP_USER=
+AG_BIDS_MCP_PASS=
+
+# --- Per-tool-call usage logging ---
+USAGE_LOG_DIR=/app/var/logs
+USAGE_LOG_KEEP_DAYS=90