soul loop-2: session events, conversation persistence, richer health + inbox

- soul.el: emit_session_start_event() logs structured InternalStateEvent on every boot; pre-serve snapshot saves boot-time graph mutations before any requests arrive
- routes.el: /health now returns boot count, node/edge counts, pulse; /api/sessions endpoint surfaces session-start history
- awareness.el: perceive() tries soul-inbox-pending then soul-inbox fallback, catches both tagging conventions
- chat.el: conv_history_persist/load provide cross-restart conversation continuity via engram

routes.el

@@ -22,7 +22,18 @@ fn err_405(method: String, path: String) -> String {
 
 fn route_health() -> String {
     let cgi_id: String = state_get("soul_cgi_id")
-    return "{\"status\":\"alive\",\"cgi_id\":\"" + cgi_id + "\"}"
+    let boot: String = state_get("soul_boot_count")
+    let boot_num: String = if str_eq(boot, "") { "0" } else { boot }
+    let node_ct: Int = engram_node_count()
+    let edge_ct: Int = engram_edge_count()
+    let pulse: String = state_get("soul.pulse")
+    let pulse_num: String = if str_eq(pulse, "") { "0" } else { pulse }
+    return "{\"status\":\"alive\""
+        + ",\"cgi_id\":\"" + cgi_id + "\""
+        + ",\"boot\":" + boot_num
+        + ",\"node_count\":" + int_to_str(node_ct)
+        + ",\"edge_count\":" + int_to_str(edge_ct)
+        + ",\"pulse\":" + pulse_num + "}"
 }
 
 fn route_lineage() -> String {
@@ -184,6 +195,13 @@ fn handle_dharma_recv(body: String) -> String {
     return "{\"error\":\"unknown event_type\",\"event_type\":\"" + eff_event + "\"}"
 }
 
+fn route_sessions() -> String {
+    let results: String = engram_search_json("session-start", 20)
+    if str_eq(results, "") { return "[]" }
+    if str_eq(results, "[]") { return "[]" }
+    return results
+}
+
 fn handle_request(method: String, path: String, body: String) -> String {
     let clean: String = strip_query(path)
 
@@ -195,6 +213,9 @@ fn handle_request(method: String, path: String, body: String) -> String {
         if str_eq(clean, "/health") {
             return route_health()
         }
+        if str_eq(clean, "/api/sessions") {
+            return route_sessions()
+        }
         if str_eq(clean, "/lineage") {
             return route_lineage()
         }