A run says whether the dashboard, the CLI or a script asked for it

`POST /runs/flows/{name}` hardcoded `cause: "api"`, so every row in the
history claimed the same origin. The body now carries an optional `cause`,
closed to the values the column knows — the dashboard sends nothing and stays
"api", `fluksio run` says "cli", and the SDK client says "sdk".

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013Gf7WaExcJ9bs3kfJXB3nK

backend/fluksio/api/routes/runs.py

@@ -6,7 +6,7 @@ or to listen on the flow socket, which carries its start and finish.
 """
 
 from datetime import UTC, datetime
-from typing import Any
+from typing import Any, Literal
 
 from fastapi import APIRouter, Depends, HTTPException, Request
 from fastapi.concurrency import run_in_threadpool
@@ -35,6 +35,12 @@ def elapsed_ms(since: datetime) -> float:
     return round((datetime.now(UTC) - start).total_seconds() * 1000, 2)
 
 
+#: Where a caller may say a run came from. "sweep" is not here because the
+#: sweep route writes it itself, and neither is a value a client made up: the
+#: column is only worth a table row if it means the same thing every time.
+RunCause = Literal["api", "cli", "sdk"]
+
+
 class RunCreate(BaseModel):
     params: dict[str, Any] = Field(default_factory=dict)
     seed: int | None = None
@@ -42,6 +48,8 @@ class RunCreate(BaseModel):
     draft: bool = False
     #: Execute every node, whatever an earlier run already worked out.
     no_cache: bool = False
+    #: Who is asking. The dashboard leaves it, and is the "api" default.
+    cause: RunCause = "api"
 
 
 class SweepEntry(BaseModel):
@@ -172,7 +180,7 @@ async def create_run(
             name,
             params=body.params,
             seed=body.seed,
-            cause="api",
+            cause=body.cause,
             actor=user.email,
             draft=body.draft,
             no_cache=body.no_cache,