fix(ci): make Spot runner names unique per dispatch

runnerName used runID[:12], which for a given commit always collapsed to
e.g. `spot-deploy-7fa70fc-depl` — so a single push triggering both
deploy-arikigame and release (both runs-on: deploy), or any same-commit
rerun, registered colliding runner names and confused task routing.

Use the full runID (sha+workflow+ms), sanitised for the runner-name charset.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

orchestrator/dispatch/main.go

@@ -302,7 +302,13 @@ func startSpotRunner(ctx context.Context, c cfg, label, runID string) (string, e
 		return "", fmt.Errorf("unknown label: %s", label)
 	}
 
-	runnerName := fmt.Sprintf("spot-%s-%s", label, runID[:12])
+	// runID = "<sha7>-<workflow>-<ms>" already encodes everything unique.
+	// The old runID[:12] truncation collapsed every deploy of a commit to the
+	// same name (e.g. deploy-arikigame + release on one push), confusing task
+	// routing and same-commit reruns. Use the full runID, sanitised for the
+	// runner-name charset (no dots/slashes from workflow filenames).
+	safeID := strings.NewReplacer(".", "-", "/", "-").Replace(runID)
+	runnerName := fmt.Sprintf("spot-%s-%s", label, safeID)
 	userData := userDataScript(c, label, runnerName)
 
 	client := ec2.NewFromConfig(awsCfg)