feat: reference implementation for files API (#2330)

# What does this PR do?
TSIA
Added Files provider to the fireworks template. Might want to add to all
templates as a follow-up.

## Test Plan
llama-stack pytest tests/unit/files/test_files.py

llama-stack llama stack build --template fireworks --image-type conda
--run
LLAMA_STACK_CONFIG=http://localhost:8321 pytest -s -v
tests/integration/files/

llama_stack/templates/fireworks/fireworks.py

@@ -13,6 +13,7 @@ from llama_stack.distribution.datatypes import (
     ShieldInput,
     ToolGroupInput,
 )
+from llama_stack.providers.inline.files.localfs.config import LocalfsFilesImplConfig
 from llama_stack.providers.inline.inference.sentence_transformers import (
     SentenceTransformersInferenceConfig,
 )
@@ -36,6 +37,7 @@ def get_distribution_template() -> DistributionTemplate:
         "eval": ["inline::meta-reference"],
         "datasetio": ["remote::huggingface", "inline::localfs"],
         "scoring": ["inline::basic", "inline::llm-as-judge", "inline::braintrust"],
+        "files": ["inline::localfs"],
         "tool_runtime": [
             "remote::brave-search",
             "remote::tavily-search",
@@ -62,6 +64,11 @@ def get_distribution_template() -> DistributionTemplate:
         provider_type="inline::faiss",
         config=FaissVectorIOConfig.sample_run_config(f"~/.llama/distributions/{name}"),
     )
+    files_provider = Provider(
+        provider_id="meta-reference-files",
+        provider_type="inline::localfs",
+        config=LocalfsFilesImplConfig.sample_run_config(f"~/.llama/distributions/{name}"),
+    )
 
     available_models = {
         "fireworks": MODEL_ENTRIES,
@@ -104,6 +111,7 @@ def get_distribution_template() -> DistributionTemplate:
                 provider_overrides={
                     "inference": [inference_provider, embedding_provider],
                     "vector_io": [vector_io_provider],
+                    "files": [files_provider],
                 },
                 default_models=default_models + [embedding_model],
                 default_shields=[ShieldInput(shield_id="meta-llama/Llama-Guard-3-8B")],
@@ -116,6 +124,7 @@ def get_distribution_template() -> DistributionTemplate:
                         embedding_provider,
                     ],
                     "vector_io": [vector_io_provider],
+                    "files": [files_provider],
                     "safety": [
                         Provider(
                             provider_id="llama-guard",