nomos+web: streaming, provider routing, event gap-fill, embedded UI; fix approval FK & session context

Agent (cmd/nomos):
- Stream LLM tokens via NewStreaming; emit text_delta then final text.
- OpenRouter provider routing: data_collection=deny (ZDR) + require_parameters;
  NOMOS_PROVIDER_SORT opt-in; Exacto via model suffix.
- Multi-turn: reload session history into context; UI passes session id.
- Fix agent_activity logging (agent_id/session_id) and mcpClient data race.

Events (live control-room feed):
- approval.created (mcp), approval.decided (api), execution.completed/failed
  (approved-action path), signal.raised/resolved + health.changed (scheduler,
  transition-gated).

Fixes:
- createApproval FK violation (reuse execution entity) — the agent's only
  write path; log the previously-swallowed errors.

Web UI:
- Embed web/dist via //go:embed (single binary); Dockerfile builds SPA into
  the Go stage; committed .gitkeep placeholder keeps backend-only builds green.
- Caddy: Authentik-gated /agent/* -> nomos so the UI reaches the agent
  same-origin in production.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

internal/httpapi/phase3.go

@@ -122,6 +122,16 @@ func resolveHostSSH(ctx context.Context, pool *db.Pool, entitySlug string) (stri
 
 // executeApprovedAction runs a gated action after operator approval.
 // Runs in a background goroutine to not block the HTTP response.
+// emitExecutionEvent records an execution lifecycle event for SSE fan-out so
+// the control room can watch approved actions run to completion live.
+func emitExecutionEvent(ctx context.Context, pool *db.Pool, execID uuid.UUID, status string, detail map[string]any) {
+	severity := "info"
+	if status == "failed" {
+		severity = "warning"
+	}
+	_ = observability.Event(ctx, sqlcgen.New(pool), "execution."+status, &execID, severity, "actuator", "", detail)
+}
+
 func executeApprovedAction(ctx context.Context, pool *db.Pool, execID uuid.UUID, targetSlug string, actionStr string) {
 	slog.Info("httpapi: executing approved action", "execution_id", execID, "target", targetSlug, "action", actionStr)
 
@@ -130,6 +140,7 @@ func executeApprovedAction(ctx context.Context, pool *db.Pool, execID uuid.UUID,
 		slog.Error("httpapi: resolve host for approved execution", "error", err, "target", targetSlug)
 		pool.Exec(ctx, `UPDATE executions SET status='failed', result=$2::jsonb WHERE entity_id=$1`,
 			execID, fmt.Sprintf(`{"error":"%s"}`, err.Error()))
+		emitExecutionEvent(ctx, pool, execID, "failed", map[string]any{"target": targetSlug, "error": err.Error()})
 		return
 	}
 
@@ -186,6 +197,10 @@ func executeApprovedAction(ctx context.Context, pool *db.Pool, execID uuid.UUID,
 	pool.Exec(ctx, `UPDATE executions SET status=$2, result=$3::jsonb, duration_ms=$4, verified=$5, started_at=$6, completed_at=$7 WHERE entity_id=$1`,
 		execID, status, result, durationMs, verified, startedAt, time.Now())
 
+	emitExecutionEvent(ctx, pool, execID, status, map[string]any{
+		"action": action, "target": targetSlug, "duration_ms": durationMs,
+	})
+
 	slog.Info("httpapi: approved action executed",
 		"execution_id", execID, "action", action, "status", status, "duration_ms", durationMs)
 }
@@ -947,6 +962,12 @@ func (s *Server) DecideApproval(ctx context.Context, req gen.DecideApprovalReque
 		return nil, auditErr
 	}
 
+	// Emit for SSE fan-out (in-tx; NOTIFY fires post-commit).
+	if evErr := observability.Event(ctx, q, "approval.decided", &id, "info", "api", "",
+		map[string]any{"decision": status, "actor": actor}); evErr != nil {
+		return nil, evErr
+	}
+
 	// On approve: execute the linked gated command.
 	if status == "approved" {
 		var execID, targetID uuid.UUID