perf: quick wins for pipeline, jobs, httpapi and web ops

- CDN snapshot: batch merge после parallel fetch, без race на persist
- ListRevisionPrefixes: лёгкая проверка revision вместо GetRevision
- Jobs: timeout/cancel context для pipeline и deploy
- HTTP server timeouts; кэш birdc для GET /peers
- ListModules: batch DoH profiles одним запросом
- Web: tab-scoped load на /operations, debounce job search, меньше over-fetch на dashboard

Co-authored-by: Cursor <[email protected]>

internal/repository/postgres.go

@@ -126,6 +126,7 @@ func (p *Postgres) ListModules(tenantID string) []*store.Module {
 	}
 	defer rows.Close()
 	var out []*store.Module
+	moduleByID := make(map[string]*store.Module)
 	for rows.Next() {
 		var m store.Module
 		m.TenantID = tenantID
@@ -152,10 +153,11 @@ func (p *Postgres) ListModules(tenantID string) []*store.Module {
 			t := last.UTC()
 			m.LastRefreshedAt = &t
 		}
-		if err := p.fillModuleDohFields(ctx, &m); err != nil {
-			continue
-		}
 		out = append(out, &m)
+		moduleByID[m.ID] = &m
+	}
+	if err := p.batchFillModuleDohFields(ctx, moduleByID); err != nil {
+		return nil
 	}
 	return out
 }
@@ -685,7 +687,13 @@ func (p *Postgres) ListRevisionPrefixes(tenantID, revisionID string, cursor stri
 		}
 	}
 	ctx := context.Background()
-	if _, err := p.GetRevision(tenantID, revisionID); err != nil {
+	var one int
+	if err := p.pool.QueryRow(ctx, `
+		SELECT 1 FROM config_revision WHERE id = $1::uuid AND tenant_id = $2::uuid`,
+		revisionID, tenantID).Scan(&one); err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, "", false
+		}
 		return nil, "", false
 	}
 	rows, err := p.pool.Query(ctx, `