store: give ecosystem traces their own table

Traces were written as facts. A single Praxis action wrote several of
them, so machine-rate rows crowded out the bounded fact readers that
humans and evaluation consume. The habit profile window of 2000 facts
and the memeval snapshot both filled with call records instead of what
Maven learned about the owner. Traces now go to ecosystem_traces, with
correlation, causation, duration and HTTP status as columns, pruned to
the most recent 5000. The new reader is exposed over IPC and rendered
as the Calls card on the ecosystem page, so it is a table someone
actually looks at.

Found in review of #84.

cmd/mavweb/ecosystem.go

@@ -8,6 +8,8 @@ import (
 	"net/http"
 	"sync"
 	"time"
+
+	"github.com/kami/maven/internal/ipc"
 )
 
 // The three sibling services Maven coordinates are headless JSON APIs (no web UI
@@ -84,9 +86,13 @@ type ecoData struct {
 	Nexus  ecoPanel[ecoEntity]
 	Praxis ecoPanel[ecoItem]
 	Hexis  ecoPanel[ecoCap]
+	Calls  ecoPanel[ipc.EcosystemTrace]
 }
 
-func handleEcosystem(w http.ResponseWriter, r *http.Request, urls ecoURLs) {
+// handleEcosystem renders the three sibling panels plus Maven's own log of the
+// calls she made to them. The call log comes from core, not from the siblings:
+// it is what Maven saw, including the hops that never got an answer.
+func handleEcosystem(w http.ResponseWriter, r *http.Request, urls ecoURLs, core ipc.CoreAPI) {
 	ctx := r.Context()
 	var d ecoData
 	var wg sync.WaitGroup
@@ -102,6 +108,15 @@ func handleEcosystem(w http.ResponseWriter, r *http.Request, urls ecoURLs) {
 	go func() { defer wg.Done(); d.Hexis.Err = getEco(ctx, urls.hexis, "/api/v1/capabilities", &d.Hexis.Rows) }()
 	wg.Wait()
 
+	if core == nil {
+		d.Calls.Err = "not configured"
+	} else if rows, err := core.RecentEcosystemTraces(ctx, 50); err != nil {
+		log.Printf("ecosystem traces: %v", err)
+		d.Calls.Err = "core read failed"
+	} else {
+		d.Calls.Rows = rows
+	}
+
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	if err := ecosystemTmpl.Execute(w, d); err != nil {
 		log.Printf("ecosystem render: %v", err)