feat: prepend breadcrumb comment to all SQL queries (DX-117497) (#9)

## Summary
- All SQL submitted through `dremio-cli` now carries a leading
breadcrumb comment: `/* dremio-cli: submitter=cli */ <user SQL>`
- Enables backend query attribution — the Jobs service can detect
CLI-originated queries, consistent with how `dremio-mcp` uses `/*
dremioai: submitter=agent */`
- Applied in the single `submit_sql()` method in `client.py`, so every
command that runs SQL (query, job, schema, folder, reflection) gets it
automatically

## Test plan
- [x] 2 new tests in `test_client.py` verify breadcrumb is prepended
(with and without context)
- [x] Full test suite passes (140/140)
- [ ] Manual: run `dremio query run "SELECT 1"` against Dremio Cloud and
verify the breadcrumb appears in the job's SQL via
`sys.project.history.jobs`

JIRA: [DX-117497](https://dremio.atlassian.net/browse/DX-117497)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

[DX-117497]:
https://dremio.atlassian.net/browse/DX-117497?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aniket-s-kulkarni

src/drs/client.py

@@ -164,7 +164,7 @@ async def delete_project(self, project_id: str) -> dict:
 
     async def submit_sql(self, sql: str, context: list[str] | None = None) -> dict:
         """Submit a SQL query. Returns job metadata including job_id."""
-        body: dict[str, Any] = {"sql": sql}
+        body: dict[str, Any] = {"sql": f"/* dremio-cli: submitter=cli */ {sql}"}
         if context:
             body["context"] = context
         return await self._post(self._v0("/sql"), json=body)

tests/test_client.py

@@ -17,6 +17,7 @@
 
 from __future__ import annotations
 
+import httpx
 import pytest
 
 from drs.auth import DrsConfig
@@ -100,3 +101,41 @@ def test_auth_header(self, client: DremioClient) -> None:
 
     def test_content_type(self, client: DremioClient) -> None:
         assert client._client.headers["content-type"] == "application/json"
+
+
+class TestSQLBreadcrumb:
+    @pytest.mark.asyncio
+    async def test_submit_sql_prepends_breadcrumb(self, client: DremioClient) -> None:
+        """SQL submitted via the client must carry the dremio-cli breadcrumb comment."""
+        captured: dict = {}
+
+        async def _capture(request: httpx.Request) -> httpx.Response:
+            import json
+
+            captured["body"] = json.loads(request.content)
+            return httpx.Response(200, json={"id": "job-1"})
+
+        client._client = httpx.AsyncClient(transport=httpx.MockTransport(_capture))
+
+        await client.submit_sql("SELECT 1")
+
+        assert captured["body"]["sql"] == "/* dremio-cli: submitter=cli */ SELECT 1"
+
+    @pytest.mark.asyncio
+    async def test_submit_sql_breadcrumb_with_context(self, client: DremioClient) -> None:
+        """Breadcrumb should be present even when a schema context is provided."""
+        captured: dict = {}
+
+        async def _capture(request: httpx.Request) -> httpx.Response:
+            import json
+
+            captured["body"] = json.loads(request.content)
+            return httpx.Response(200, json={"id": "job-2"})
+
+        client._client = httpx.AsyncClient(transport=httpx.MockTransport(_capture))
+
+        await client.submit_sql("SELECT * FROM orders", context=["myspace"])
+
+        assert captured["body"]["sql"].startswith("/* dremio-cli: submitter=cli */")
+        assert "SELECT * FROM orders" in captured["body"]["sql"]
+        assert captured["body"]["context"] == ["myspace"]