feat: add OpenHerbarium MCP server core

src/openherbarium_mcp/rhs.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+from typing import Any
+from urllib.parse import quote_plus
+
+from .models import evidence, utc_now_iso
+
+RHS_SOURCE = "Royal Horticultural Society"
+
+CARE_TOPICS = ["light", "temperature", "humidity", "watering", "substrate", "fertilisation", "repotting"]
+
+
+def rhs_care_source_candidates(name: str) -> dict[str, Any]:
+    """Return RHS search/source candidates without turning them into care recommendations."""
+    query = quote_plus(name)
+    base_url = f"https://www.rhs.org.uk/search?query={query}"
+    return {
+        "status": "source_candidates",
+        "source": RHS_SOURCE,
+        "retrieved_at": utc_now_iso(),
+        "records": [
+            {
+                "topic": topic,
+                "value": evidence(
+                    f"RHS search candidate for {topic}; fetch and verify before use.",
+                    source=RHS_SOURCE,
+                    url=base_url,
+                    confidence="low",
+                ),
+            }
+            for topic in CARE_TOPICS
+        ],
+    }