Tool retrieval: catch 'add X to (my) contacts' / 'address book' phrasings

The literal phrase 'add to contacts' missed when there was a name
between 'add' and 'to', e.g. 'add Pat to my contacts'. Anchor on the
tail with 'to my contacts', 'to contacts', 'to address book' so word
boundaries fire regardless of what sits in front.

src/tool_index.py

@@ -372,6 +372,10 @@ class ToolIndex:
         frozenset({"save contact", "add contact", "new contact", "update contact",
                    "edit contact", "delete contact", "remove contact",
                    "save this person", "add to contacts", "save to contacts",
+                   # "add <name> to (my) contacts" — words between 'add' and
+                   # 'contacts' break the literal phrase match above, so anchor
+                   # on the tail.
+                   "to my contacts", "to contacts", "to address book",
                    # "save this for <person>" / "save it for <person>" — the user
                    # is storing info on a known person without using the literal
                    # word 'contact'. Catches the address/phone-paste pattern.