A run keeps the inputs its flow declared at submit

Run.declared (migration 2e7ca7d10044) snapshots the declarations on submit
and import. The run detail's Inputs panel reads them, and a run from before
falls back to the flow's current declarations.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx

backend/fluksio/api/routes/runs.py

@@ -210,6 +210,10 @@ class RunRow(BaseModel):
 class RunDetail(RunRow):
     result: dict[str, Any] = Field(default_factory=dict)
     flow_version: int = 1
+    #: The inputs the flow declared when this was submitted, with their
+    #: declared values. Null for a run from before this was kept, which reads
+    #: against the flow's current declarations instead.
+    declared: dict[str, Any] | None = None
     nodes: list[RunNodeRow] = Field(default_factory=list)
     artifacts: list[ArtifactRow] = Field(default_factory=list)