refactor(browser): split installation and profile abstractions (#603)

* refactor(browser): split installation and profile abstractions

A Chromium installation shares one master key across its profiles, but
modeling each profile as its own Browser re-derived the key per profile.
Browser now represents one installation holding its profiles and derives
the key once; new types.Profile/ExtractResult/CountResult carry per-profile
results.

* style: gofumpt safari_test.go

* test(chromium): rename shadowed loop var to path

browser/chromium/profile_test.go

@@ -0,0 +1,119 @@
+package chromium
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/moond4rk/hackbrowserdata/crypto/keyretriever"
+	"github.com/moond4rk/hackbrowserdata/filemanager"
+	"github.com/moond4rk/hackbrowserdata/types"
+)
+
+// TestExtractCategory_CustomExtractor verifies that extractCategory dispatches
+// through a registered extractor instead of the default switch logic.
+func TestExtractCategory_CustomExtractor(t *testing.T) {
+	// Create a profile with a custom extractor that records it was called
+	called := false
+	testExtractor := extensionExtractor{
+		fn: func(path string) ([]types.ExtensionEntry, error) {
+			called = true
+			return []types.ExtensionEntry{{Name: "custom", ID: "test-id"}}, nil
+		},
+	}
+
+	p := &profile{
+		extractors: map[types.Category]categoryExtractor{
+			types.Extension: testExtractor,
+		},
+	}
+
+	data := &types.BrowserData{}
+	p.extractCategory(data, types.Extension, keyretriever.MasterKeys{}, "unused-path")
+
+	assert.True(t, called, "custom extractor should be called")
+	require.Len(t, data.Extensions, 1)
+	assert.Equal(t, "custom", data.Extensions[0].Name)
+}
+
+// TestExtractCategory_DefaultFallback verifies that extractCategory uses
+// the default switch when no extractor is registered.
+func TestExtractCategory_DefaultFallback(t *testing.T) {
+	path := createTestDB(t, "History", urlsSchema,
+		insertURL("https://example.com", "Example", 3, 13350000000000000),
+	)
+
+	p := &profile{
+		extractors: nil, // no custom extractors
+	}
+
+	data := &types.BrowserData{}
+	p.extractCategory(data, types.History, keyretriever.MasterKeys{}, path)
+
+	require.Len(t, data.Histories, 1)
+	assert.Equal(t, "Example", data.Histories[0].Title)
+}
+
+// ---------------------------------------------------------------------------
+// acquireFiles
+// ---------------------------------------------------------------------------
+
+func TestAcquireFiles(t *testing.T) {
+	profileDir := filepath.Join(fixture.chrome, "Default")
+	resolved := resolveSourcePaths(chromiumSources, profileDir)
+
+	p := &profile{profileDir: profileDir, sourcePaths: resolved}
+
+	session, err := filemanager.NewSession()
+	require.NoError(t, err)
+	defer session.Cleanup()
+
+	cats := []types.Category{types.History, types.Cookie, types.Bookmark}
+	paths := p.acquireFiles(session, cats)
+
+	assert.Len(t, paths, len(cats))
+	for _, path := range paths {
+		_, err := os.Stat(path)
+		require.NoError(t, err, "acquired file should exist")
+	}
+}
+
+func TestCountCategory(t *testing.T) {
+	t.Run("History", func(t *testing.T) {
+		path := setupHistoryDB(t)
+		p := &profile{kind: types.Chromium}
+		assert.Equal(t, 3, p.countCategory(types.History, path))
+	})
+
+	t.Run("Cookie", func(t *testing.T) {
+		path := setupCookieDB(t)
+		p := &profile{kind: types.Chromium}
+		assert.Equal(t, 2, p.countCategory(types.Cookie, path))
+	})
+
+	t.Run("Bookmark", func(t *testing.T) {
+		path := setupBookmarkJSON(t)
+		p := &profile{kind: types.Chromium}
+		assert.Equal(t, 3, p.countCategory(types.Bookmark, path))
+	})
+
+	t.Run("Extension_Opera", func(t *testing.T) {
+		path := createTestJSON(t, "Secure Preferences", `{
+			"extensions": {
+				"opsettings": {
+					"ext1": {"location": 1, "manifest": {"name": "Ext", "version": "1.0"}}
+				}
+			}
+		}`)
+		p := &profile{kind: types.ChromiumOpera}
+		assert.Equal(t, 1, p.countCategory(types.Extension, path))
+	})
+
+	t.Run("FileNotFound", func(t *testing.T) {
+		p := &profile{kind: types.Chromium}
+		assert.Equal(t, 0, p.countCategory(types.History, "/nonexistent/path"))
+	})
+}