Contacts: postal-address support via vCard ADR, keep tool prompt minimal

Closes the gap that pushed the agent into manage_memory when the user
pasted an address and said 'save this for X'. manage_contact now
accepts an optional address arg end-to-end:

- routes/contacts_routes.py:
  - _normalize_contact carries an 'address' field
  - _build_vcard emits ADR:;;<address>;;;; (street component of the
    RFC-6350 7-part ADR), only when address is non-empty
  - _parse_vcards reads ADR, joins non-empty components with ', '
  - _create_contact and _update_contact thread address through;
    update preserves existing address when caller passes empty
- src/tool_implementations.py do_manage_contact:
  - add accepts address; require at least name+address or email
    (was: email required) so address-only contacts are addable
  - update accepts address; require name OR emails OR address
- src/tool_schemas.py: schema gets a single 'address' string field
- src/tool_index.py + src/agent_loop.py: descriptions get one
  'address' arg mention and a 'use this for save-X-for-person /
  address pastes / phone-with-name' steering line. Net: a few
  bytes added, not a paragraph.

Also: removed a stray name from the schema's manage_contact example
strings ('save Jonathan's email…') — no real names in the codebase.

src/tool_schemas.py

@@ -1014,7 +1014,7 @@ FUNCTION_TOOL_SCHEMAS = [
         "type": "function",
         "function": {
             "name": "manage_contact",
-            "description": "Create, update, delete, or list the user's CardDAV contacts. Use to save a new contact ('save Jonathan's email jon@x.com'), update an existing one ('change Maria's number'), or remove one. For update/delete you need the contact's uid — call action='list' first to find it. Writes go through the same dedupe + validation as the Contacts UI.",
+            "description": "Create, update, delete, or list the user's CardDAV contacts. Use to save a new contact, update an existing one (email/phone/address), or remove one. For update/delete you need the contact's uid — call action='list' first to find it. Writes go through the same dedupe + validation as the Contacts UI.",
             "parameters": {
                 "type": "object",
                 "properties": {
@@ -1025,6 +1025,7 @@ FUNCTION_TOOL_SCHEMAS = [
                     "email": {"type": "string", "description": "Single email address (convenience for add, or the primary email for update)."},
                     "emails": {"type": "array", "items": {"type": "string"}, "description": "Full list of email addresses (for update; first is primary)."},
                     "phones": {"type": "array", "items": {"type": "string"}, "description": "Full list of phone numbers (for update)."},
+                    "address": {"type": "string", "description": "Postal/mailing address as a single human-readable string."},
                 },
                 "required": ["action"]
             }