sync file-type support across upload/convert and fix collected_at timezone handling

internal/parser/parser_test.go

@@ -2,6 +2,7 @@ package parser
 
 import (
 	"testing"
+	"time"
 
 	"git.mchus.pro/mchus/logpile/internal/models"
 )
@@ -32,3 +33,30 @@ func TestAppendExtractionWarnings(t *testing.T) {
 		t.Fatalf("expected warning details in RawData")
 	}
 }
+
+func TestInferCollectedAtFromExtractedFiles_PrefersReliableMTime(t *testing.T) {
+	files := []ExtractedFile{
+		{Path: "a.log", ModTime: time.Date(1980, 1, 1, 0, 0, 0, 0, time.UTC)},
+		{Path: "b.log", ModTime: time.Date(2025, 12, 12, 10, 14, 49, 0, time.FixedZone("EST", -5*3600))},
+		{Path: "c.log", ModTime: time.Date(2026, 2, 28, 4, 18, 18, 0, time.FixedZone("UTC+8", 8*3600))},
+	}
+
+	got := inferCollectedAtFromExtractedFiles(files)
+	want := files[2].ModTime
+	if !got.Equal(want) {
+		t.Fatalf("expected %s, got %s", want, got)
+	}
+}
+
+func TestInferCollectedAtFromExtractedFiles_FallsBackToAnyMTime(t *testing.T) {
+	files := []ExtractedFile{
+		{Path: "a.log", ModTime: time.Date(1980, 1, 1, 0, 0, 0, 0, time.UTC)},
+		{Path: "b.log", ModTime: time.Date(1970, 1, 2, 0, 0, 0, 0, time.UTC)},
+	}
+
+	got := inferCollectedAtFromExtractedFiles(files)
+	want := files[0].ModTime
+	if !got.Equal(want) {
+		t.Fatalf("expected fallback %s, got %s", want, got)
+	}
+}