feat(api): add readonly connectors API (#4258)

# What does this PR do?
Adds a new API for connectors and MCP registry support along with
required types.
Does not include any implementation for it

<!-- If resolving an issue, uncomment and update the line below -->
Closes #4235 and #4061 (partially)

## Test Plan
no tests included

---------

Signed-off-by: Jaideep Rao <jrao@redhat.com>
Co-authored-by: Francisco Javier Arceo <arceofrancisco@gmail.com>

src/llama_stack/core/datatypes.py

@@ -23,6 +23,7 @@ from llama_stack_api import (
     Api,
     Benchmark,
     BenchmarkInput,
+    ConnectorInput,
     Dataset,
     DatasetInput,
     DatasetIO,
@@ -455,6 +456,7 @@ class RegisteredResources(BaseModel):
     scoring_fns: list[ScoringFnInput] = Field(default_factory=list)
     benchmarks: list[BenchmarkInput] = Field(default_factory=list)
     tool_groups: list[ToolGroupInput] = Field(default_factory=list)
+    connectors: list[ConnectorInput] = Field(default_factory=list)
 
 
 class ServerConfig(BaseModel):

src/llama_stack/core/distribution.py

@@ -25,7 +25,7 @@ from llama_stack_api import (
 logger = get_logger(name=__name__, category="core")
 
 
-INTERNAL_APIS = {Api.inspect, Api.providers, Api.prompts, Api.conversations}
+INTERNAL_APIS = {Api.inspect, Api.providers, Api.prompts, Api.conversations, Api.connectors}
 
 
 def stack_apis() -> list[Api]:

src/llama_stack/core/resolver.py

@@ -28,6 +28,7 @@ from llama_stack_api import (
     Batches,
     Benchmarks,
     BenchmarksProtocolPrivate,
+    Connectors,
     Conversations,
     DatasetIO,
     Datasets,
@@ -100,6 +101,7 @@ def api_protocol_map(external_apis: dict[Api, ExternalApiSpec] | None = None) ->
         Api.files: Files,
         Api.prompts: Prompts,
         Api.conversations: Conversations,
+        Api.connectors: Connectors,
     }
 
     if external_apis: