sqlite-vec support for Responses file_search

This wires up the Files API optional dependency into sqlite_vec and
adds the localfs Files provider to our starter template, so that
Responses API file_search tool works out of the box for sqlite_vec in
that template.

Some additional testing with this provider plus some other inference
models led me to loosen the verification test results checking a bit -
not for the tool call, but just around the assistant response with the
file_search tool call. Some providers, such as OpenAI SaaS, make
multiple tool calls to resolve the query sometimes, especially when it
cannot find an answer so tries a few permutations before returning
empty results to the user in that test.

Signed-off-by: Ben Browning <bbrownin@redhat.com>

llama_stack/templates/starter/build.yaml

@@ -17,6 +17,8 @@ distribution_spec:
     - inline::sqlite-vec
     - remote::chromadb
     - remote::pgvector
+    files:
+    - inline::localfs
     safety:
     - inline::llama-guard
     agents: