refactor(tests): merge detect_suggested_procedure into expected_detection

Two overlapping TestTemplate fields (expected_detection: narrative
guidance from imports/leads; detect_suggested_procedure: concrete
commands from approved suggestions) are now one. Blue-side procedure
suggestions target expected_detection directly, appending onto
whatever is already there rather than overwriting it — same
merge-not-overwrite behavior already used for the red side. Existing
detect_suggested_procedure data is folded into expected_detection
before the column is dropped.

frontend/src/api/test-templates.ts

@@ -24,7 +24,6 @@ export interface CreateTemplatePayload {
   source_url?: string;
   attack_procedure?: string;
   expected_detection?: string;
-  detect_suggested_procedure?: string;
   platform?: string;
   tool_suggested?: string;
   severity?: string;