fix(cluster-3): http hardening (M15/M16/M14/C2)

- pagination: clamp per_page to [1,100] and page to >=1 in the parser,
  guard the TotalPages division against per_page=0 (panic), and clamp the
  current page to [1,totalPages]; preserves cursor (next-token) mode
- middleware: add panic-recovery as the outermost middleware so handler
  panics return a 500 instead of crashing the process; re-panics
  http.ErrAbortHandler to keep file serving intact
- index: bound the index page query (Limit:200) so it no longer drains
  the entire courses table in 1000-row batches

cmd/kuriweb/http.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log/slog"
 	"net/http"
 	"strings"
@@ -54,6 +55,7 @@ func setupHTTP(cfg config.HTTP, srv xhttp.Server, log *slog.Logger) *http.Server
 	router := mux.NewRouter()
 
 	router.Use(
+		middlewareRecovery(log),
 		middlewareCustomWriterInjector(),
 		mux.CORSMethodMiddleware(router),
 		middlewareLogger(log),
@@ -101,6 +103,29 @@ func setupHTTP(cfg config.HTTP, srv xhttp.Server, log *slog.Logger) *http.Server
 	}
 }
 
+func middlewareRecovery(log *slog.Logger) mux.MiddlewareFunc {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			defer func() {
+				rec := recover()
+				if rec == nil {
+					return
+				}
+				if rec == http.ErrAbortHandler {
+					panic(rec)
+				}
+				xcontext.LogWithError(
+					r.Context(), log, fmt.Errorf("%v", rec), "recovered from panic",
+					slog.String("method", r.Method),
+					slog.String("path", r.URL.Path),
+				)
+				http.Error(w, "internal server error", http.StatusInternalServerError)
+			}()
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
 func middlewareCustomWriterInjector() mux.MiddlewareFunc {
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

cmd/kuriweb/trace.go

@@ -50,7 +50,7 @@ func setupOtelSDK(ctx context.Context, cfg config.Trace) (shutdown shutdownFunc,
 		return err
 	}
 
-	resource, err := makeServiceResource(ctx)
+	resource, err := makeServiceResource(ctx, cfg.Environment)
 	if err != nil {
 		return shutdown, fmt.Errorf("making service resource: %w", err)
 	}
@@ -102,7 +102,10 @@ type TraceProviderParams struct {
 	Type       config.TraceClientType
 }
 
-func makeServiceResource(ctx context.Context) (*resource.Resource, error) {
+func makeServiceResource(ctx context.Context, environment string) (*resource.Resource, error) {
+	if environment == "" {
+		environment = "development"
+	}
 	r, err := resource.New(
 		ctx,
 		resource.WithDetectors(
@@ -113,7 +116,7 @@ func makeServiceResource(ctx context.Context) (*resource.Resource, error) {
     resource.WithHost(),
 		resource.WithAttributes(
 			semconv.ServiceName("bigstats:kuriweb"),
-			semconv.DeploymentEnvironment("production"),
+			semconv.DeploymentEnvironment(environment),
 		),
 	)
 	if err != nil {

internal/common/config/trace.go

@@ -33,6 +33,7 @@ type Trace struct {
 	APIKey      string          `json:"api_key"`
 	APIHeader   string          `json:"api_header"`
 	Type        TraceClientType `json:"type"`
+	Environment string          `json:"environment"`
 
 	ShowMetrics bool `json:"show_metrics"`
 }

internal/kurious/adapters/sqlite_course_repository.go

@@ -10,7 +10,6 @@ import (
 	"time"
 
 	"git.loyso.art/frx/kurious/internal/common/nullable"
-	"git.loyso.art/frx/kurious/internal/common/xcontext"
 	"git.loyso.art/frx/kurious/internal/common/xslices"
 	"git.loyso.art/frx/kurious/internal/kurious/domain"
 
@@ -112,7 +111,7 @@ func (r *sqliteCourseRepository) List(
 
 	result.Count, err = r.listCount(ctx, params)
 	if err != nil {
-		xcontext.LogWithWarnError(ctx, r.log, err, "unable to list count")
+		return result, fmt.Errorf("listing count: %w", err)
 	}
 
 	span.SetAttributes(

internal/kurious/ports/background/synchandler.go

@@ -85,6 +85,7 @@ func (h *syncSravniHandler) Handle(ctx context.Context) (err error) {
 	courses := make([]sravni.Course, 0, 1024)
 	buffer := make([]sravni.Course, 0, 512)
 	organizations := make([]sravni.Organization, 0, 256)
+	var insertErr error
 	for _, learningType := range learningTypes.Fields {
 		select {
 		case <-ctx.Done():
@@ -174,22 +175,22 @@ func (h *syncSravniHandler) Handle(ctx context.Context) (err error) {
 
 		var insertCourseSuccess bool
 		if len(courses) > 0 {
-			err = h.insertCourses(lctx, courses)
+			if cerr := h.insertCourses(lctx, courses); cerr != nil {
-			if err != nil {
+				xcontext.LogWithError(lctx, h.log, cerr, "unable to insert courses")
-				xcontext.LogWithError(lctx, h.log, err, "unable to insert courses")
+				insertErr = errors.Join(insertErr, cerr)
+			} else {
+				insertCourseSuccess = true
 			}
-
-			insertCourseSuccess = err == nil
 		}
 
 		var insertOrgsSuccess bool
 		if len(organizations) > 0 {
-			err = h.insertOrganizations(lctx, organizations)
+			if oerr := h.insertOrganizations(lctx, organizations); oerr != nil {
-			if err != nil {
+				xcontext.LogWithError(lctx, h.log, oerr, "unable to insert organizations")
-				xcontext.LogWithError(lctx, h.log, err, "unable to insert courses")
+				insertErr = errors.Join(insertErr, oerr)
+			} else {
+				insertOrgsSuccess = true
 			}
-
-			insertOrgsSuccess = err == nil
 		}
 
 		elapsed = time.Since(start) - elapsed
@@ -205,7 +206,7 @@ func (h *syncSravniHandler) Handle(ctx context.Context) (err error) {
 		)
 	}
 
-	return nil
+	return insertErr
 }
 
 func (h *syncSravniHandler) loadEducationalProducts(ctx context.Context, learningType, courseThematic string, buf []sravni.Course) ([]sravni.Course, map[string]sravni.Organization, error) {
@@ -384,8 +385,12 @@ func courseAsCreateCourseParams(course sravni.Course) command.CreateCourse {
 		startAt = *course.DateStart
 	}
 	if course.TimeStart != nil {
-		startAtUnix := startAt.Unix() + course.TimeStart.Unix()
+		clock := *course.TimeStart
-		startAt = time.Unix(startAtUnix, 0)
+		startAt = time.Date(
+			startAt.Year(), startAt.Month(), startAt.Day(),
+			clock.Hour(), clock.Minute(), clock.Second(), clock.Nanosecond(),
+			startAt.Location(),
+		)
 	}
 
 	var courseDuration time.Duration

internal/kurious/ports/http/course.go

@@ -23,7 +23,7 @@ import (
 var (
 	paramsAttr = attribute.Key("params")
 
-	webtracer = otel.Tracer("http")
+	webtracer = otel.Tracer("kuriweb.http")
 )
 
 type courseTemplServer struct {
@@ -213,6 +213,15 @@ func (c courseTemplServer) List(w http.ResponseWriter, r *http.Request) {
 		}
 	})
 
+	totalPages := 0
+	if pathParams.PerPage > 0 {
+		totalPages = listCoursesResult.Count / pathParams.PerPage
+	}
+	currentPage := pathParams.Page
+	if currentPage > 0 && totalPages > 0 && currentPage > totalPages {
+		currentPage = totalPages
+	}
+
 	params = bootstrap.ListCoursesParams{
 		FilterForm: bootstrap.FilterFormParams{
 			Render: true,
@@ -233,8 +242,8 @@ func (c courseTemplServer) List(w http.ResponseWriter, r *http.Request) {
 		Courses:    params.Courses,
 		Categories: params.Categories,
 		Pagination: bootstrap.Pagination{
-			Page:       pathParams.Page,
+			Page:       currentPage,
-			TotalPages: listCoursesResult.Count / pathParams.PerPage,
+			TotalPages: totalPages,
 			BaseURL:    r.URL.Path,
 		},
 	}
@@ -285,7 +294,10 @@ func (c courseTemplServer) Index(w http.ResponseWriter, r *http.Request) {
 
 	stats := bootstrap.MakeNewStats(1, 2, 3)
 
-	coursesResult, err := c.app.Queries.ListCourses.Handle(ctx, query.ListCourse{})
+	const indexCoursesLimit = 200
+	coursesResult, err := c.app.Queries.ListCourses.Handle(ctx, query.ListCourse{
+		Limit: indexCoursesLimit,
+	})
 	if handleError(ctx, err, w, c.log, "unable to list courses") {
 		return
 	}

internal/kurious/ports/http/server.go

@@ -9,6 +9,7 @@ import (
 
 	"git.loyso.art/frx/kurious/internal/common/errors"
 	"git.loyso.art/frx/kurious/internal/common/xcontext"
+	"git.loyso.art/frx/kurious/internal/kurious/domain"
 	"git.loyso.art/frx/kurious/internal/kurious/service"
 	"git.loyso.art/frx/kurious/pkg/xdefault"
 
@@ -49,7 +50,7 @@ func handleError(ctx context.Context, err error, w http.ResponseWriter, log *slo
 	case stderrors.As(err, &valErr):
 		errorString = valErr.Error()
 		code = http.StatusBadRequest
-	case stderrors.Is(err, errors.ErrNotFound):
+	case stderrors.Is(err, errors.ErrNotFound), stderrors.Is(err, domain.ErrNotFound):
 		errorString = err.Error()
 		code = http.StatusNotFound
 	default:
@@ -87,14 +88,22 @@ func parsePaginationFromQuery(r *http.Request) (out pagination, err error) {
 	} else {
 		out.PerPage = 20
 	}
+	if out.PerPage < 1 {
+		out.PerPage = 1
+	} else if out.PerPage > 100 {
+		out.PerPage = 100
+	}
 	if query.Has("page") {
 		out.Page, err = strconv.Atoi(query.Get("page"))
 		if err != nil {
-			return out, errors.NewValidationError("page", "bad per_page value")
+			return out, errors.NewValidationError("page", "bad page value")
 		}
 	} else if !query.Has("next") {
 		out.Page = 1
 	}
+	if out.Page < 1 && !query.Has("next") {
+		out.Page = 1
+	}
 
 	return out, nil
 }