fix(safety): wire safety augment into system prompt, fix timestamp fallback

- Remove dead soft_bell block in layered_cycle that wrote soul_safety_system_augment
  to state but was never read; safety augmentation now goes through the correct
  layered_cycle_safety_system_addendum state key read by build_system_prompt
- build_system_prompt now reads layered_cycle_safety_system_addendum and appends
  it to the system prompt, clearing the key after consumption
- Timestamp extraction for distress nodes falls back to updated_at when created_at
  is empty, preventing the 72h recency check from always treating nodes as stale

soul.el

@@ -312,15 +312,6 @@ fn layered_cycle(raw_input: String) -> String {
         json_get(steward_result, "redirect_to")
     }
 
-    // L1 safety augment: if a soft bell fired, inject the safety directive into state
-    // so imprint_respond (and build_system_prompt) can incorporate it before the LLM call.
-    // Hard bell is handled above (early exit). Here we act on soft_bell only.
-    if str_eq(screen_action, "soft_bell") {
-        let base_system: String = state_get("soul_identity")
-        let augmented: String = safety_augment_system(base_system, raw_input)
-        state_set("soul_safety_system_augment", augmented)
-    }
-
     // L3: imprint responds
     let output: String = imprint_respond(aligned, imprint_id)