Add comprehensive test suite — 81% cross-package coverage

Bug fixes:
- config: remove unused log import
- item: fix Printf format %d->%t for boolean ReadState
- util: update stale config.Read -> config.Init, remove config.Config.DBServer

Test files added:
- config/config_test.go: Init, readConfig, addDefaults (100%)
- vlog/vlog_test.go: Printf, Println verbose/silent (100%)
- models/db_test.go: InitDB tests
- models/feed/feed_test.go: CRUD, filter, Categories, NewFeed, ResolveFeedURL (87%)
- models/item/item_test.go: CRUD, Filter with category/search/starred, rewriteImages (71%)
- exporter/exporter_test.go: all export formats (91%)
- importer/importer_test.go: InsertIItem, ImportJSON (90%)
- crawler/crawler_test.go: GetFeedContent, CrawlFeed, CrawlWorker, Crawl (89%)
- web/web_test.go: auth, login/logout, stream, item, feed, category,
  export, crawl, imageProxy handlers (77%)

Remaining 0% functions require HTTP/rice.MustFindBox/main entry and
can't be unit tested without refactoring (see tickets NK-gqkh96, NK-6q9nyg).

1 files changed, 78 insertions, 0 deletions

diff --git a/vlog/vlog_test.go b/vlog/vlog_test.go
new file mode 100644
index 0000000..9def0f0
--- /dev/null
+++ b/vlog/vlog_test.go
@@ -0,0 +1,78 @@
+package vlog
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"testing"
+)
+
+func captureStdout(f func()) string {
+	old := os.Stdout
+	r, w, _ := os.Pipe()
+	os.Stdout = w
+
+	f()
+
+	w.Close()
+	os.Stdout = old
+
+	var buf bytes.Buffer
+	buf.ReadFrom(r)
+	return buf.String()
+}
+
+func TestPrintfVerbose(t *testing.T) {
+	VERBOSE = true
+	defer func() { VERBOSE = false }()
+
+	output := captureStdout(func() {
+		Printf("hello %s", "world")
+	})
+	expected := fmt.Sprintf("hello %s", "world")
+	if output != expected {
+		t.Errorf("expected %q, got %q", expected, output)
+	}
+}
+
+func TestPrintfSilent(t *testing.T) {
+	VERBOSE = false
+
+	output := captureStdout(func() {
+		Printf("hello %s", "world")
+	})
+	if output != "" {
+		t.Errorf("expected empty output when not verbose, got %q", output)
+	}
+}
+
+func TestPrintlnVerbose(t *testing.T) {
+	VERBOSE = true
+	defer func() { VERBOSE = false }()
+
+	output := captureStdout(func() {
+		Println("hello", "world")
+	})
+	expected := fmt.Sprintln("hello", "world")
+	if output != expected {
+		t.Errorf("expected %q, got %q", expected, output)
+	}
+}
+
+func TestPrintlnSilent(t *testing.T) {
+	VERBOSE = false
+
+	output := captureStdout(func() {
+		Println("hello", "world")
+	})
+	if output != "" {
+		t.Errorf("expected empty output when not verbose, got %q", output)
+	}
+}
+
+func TestInit(t *testing.T) {
+	// init() sets VERBOSE to false
+	if VERBOSE != false {
+		t.Error("VERBOSE should default to false")
+	}
+}