huskies: merge 1128 story Bounded event queues + EventStreamGap sentinel + observability for context assembly

server/src/crdt_state/lww_maps/llm_sessions.rs

@@ -14,6 +14,7 @@ use serde_json::json;
 
 use super::super::state::{apply_and_persist, get_crdt, rebuild_llm_session_index};
 use super::super::types::{LlmSessionCrdt, LlmSessionView};
+use super::event_log::GAP_PIPELINE_EVENT;
 
 /// Write or upsert an LLM session entry keyed by `session_id`.
 ///
@@ -110,7 +111,7 @@ pub fn assemble_and_advance_session(session_id: &str) -> Vec<String> {
     // Advance the high-water mark to the maximum new event_seq.
     let new_max_seq = new_events.iter().map(|(seq, ..)| *seq).max().unwrap_or(0);
     let mut new_high_water = current_high_water;
-    new_high_water.insert(local_sled_id, new_max_seq);
+    new_high_water.insert(local_sled_id.clone(), new_max_seq);
     let new_hw_json = serde_json::to_string(&new_high_water).unwrap_or_else(|_| "{}".to_string());
 
     // Upsert the session entry with the new high-water value.
@@ -135,14 +136,41 @@ pub fn assemble_and_advance_session(session_id: &str) -> Vec<String> {
         state.llm_session_index = rebuild_llm_session_index(&state.crdt);
     }
 
-    // Render each new event as a compact audit line.
+    // Observability: log event-log size and gap count for this sled.
+    let total_entries = state
+        .crdt
+        .doc
+        .event_log
+        .iter()
+        .filter(|e| matches!(e.sled_id.view(), JsonValue::String(s) if s == local_sled_id))
+        .count();
+    let gap_count = state
+        .crdt
+        .doc
+        .event_log
+        .iter()
+        .filter(|e| {
+            matches!(e.sled_id.view(), JsonValue::String(s) if s == local_sled_id)
+                && matches!(e.pipeline_event.view(), JsonValue::String(s) if s == GAP_PIPELINE_EVENT)
+        })
+        .count();
+    crate::slog!(
+        "[event-log] assemble session={session_id} sled_entries={total_entries} gap_count={gap_count}"
+    );
+
+    // Render each new event as a compact audit line; gap sentinels get a
+    // human-readable message so the LLM is never presented with raw field data.
     new_events
         .into_iter()
         .map(|(_, story_id, from_stage, to_stage, pipeline_event)| {
-            format!(
-                "pipeline_event story_id=\"{story_id}\" from=\"{from_stage}\" \
-                 to=\"{to_stage}\" event=\"{pipeline_event}\""
-            )
+            if pipeline_event == GAP_PIPELINE_EVENT {
+                format!("events between {from_stage} and {to_stage} were dropped")
+            } else {
+                format!(
+                    "pipeline_event story_id=\"{story_id}\" from=\"{from_stage}\" \
+                     to=\"{to_stage}\" event=\"{pipeline_event}\""
+                )
+            }
         })
         .collect()
 }