Record that search_customers and list_opportunities can now be paged. Both
answer with one page — the result carries hasMore and nextCursor — but neither
declared a cursor argument and both handlers passed an empty cursor, so an agent
was told there was more and had no way to ask for it.

Note that both schemas pin additionalProperties to false, so a client could not
send a cursor on its own either: everything past the first page, 50 rows by
default and 200 at most, was unreachable over MCP on an account large enough for
the limit to bite.

Record that the two tools now take a cursor, and that customerSearchArgs and
opportunityFilterArgs build the service filter beside the schema so a declared
argument cannot be dropped on the way to the query. The same function uppercases
status, which the query compares against the stored value, so a model that sent
"open" as it reads in prose now gets a match rather than an empty list.

Record that a cursor this server did not issue is refused instead of being read
as offset 0. Restarting at page one handed back a nextCursor promising more,
which is a listing that never ends; the message reaches REST as a 400.

Note that no migration is needed, that the cursor format and the 50/200 limits
are unchanged, and that only calls sending an invalid cursor behave differently.