feat: add internal/keepass package with full Backend implementation (tasks k4+l4+m4)

Read-write KeePass backend implementing backend.Backend:
- WalkIndexes flattens groups into 'Group/Title' virtual entries
- LoadData returns formatted Password/User/URL/Notes for text entries
  or raw bytes for binary attachments
- WriteBack hook enables edit round-trip through the kdbx file
- Add/Import/ImportRecursive/Remove with atomic tmp+rename save
- Binary attachments surface as virtual 'Group/Title/filename' entries;
  Add to such a path creates/replaces the attachment on the parent entry
- AtomicSave exported for reuse by cli/kdbx_store.go
- parseContent is the tolerant inverse of formatContent
- Helpers EnsureGroup, UpsertEntryByTitle, SetEntryField, SplitDescriptionPath,
  SanitizeRelativePath exported so cli/kdbx_store.go avoids duplication

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 94 insertions, 0 deletions

diff --git a/internal/keepass/fzf.go b/internal/keepass/fzf.go
new file mode 100644
index 0000000..a30e769
--- /dev/null
+++ b/internal/keepass/fzf.go
@@ -0,0 +1,94 @@
+package keepass
+
+import (
+	"context"
+	"sort"
+	"strings"
+
+	"codeberg.org/snonux/foostore/internal/picker"
+	"codeberg.org/snonux/foostore/internal/store"
+)
+
+// Fzf launches fzf and returns only the selected description.
+func (b *Backend) Fzf(ctx context.Context) (string, error) {
+	result, err := b.FzfInteractive(ctx)
+	if err != nil {
+		return "", err
+	}
+	return result.Description, nil
+}
+
+// FzfInteractive launches fzf with action key bindings and returns the
+// selected description plus the chosen action.
+func (b *Backend) FzfInteractive(ctx context.Context) (store.PickerResult, error) {
+	var indexes store.IndexSlice
+	if err := b.WalkIndexes(ctx, "", func(idx *store.Index) error {
+		indexes = append(indexes, idx)
+		return nil
+	}); err != nil {
+		return store.PickerResult{}, err
+	}
+	if len(indexes) == 0 {
+		return store.PickerResult{}, nil
+	}
+
+	sort.Sort(indexes)
+	entries := buildPickerEntries(indexes)
+	return runFzfInteractive(ctx, entries)
+}
+
+// buildPickerEntries converts a sorted IndexSlice into picker.Entry rows.
+func buildPickerEntries(indexes store.IndexSlice) []picker.Entry {
+	entries := make([]picker.Entry, 0, len(indexes))
+	for i, idx := range indexes {
+		kind := "TEXT"
+		if idx.IsBinary() {
+			kind = "BINARY"
+		}
+		hashSuffix := ""
+		if len(idx.Hash) >= 63 {
+			hashSuffix = idx.Hash[53:63]
+		}
+		entries = append(entries, picker.Entry{
+			RowID:       i + 1,
+			Description: idx.Description,
+			Kind:        kind,
+			HashSuffix:  hashSuffix,
+		})
+	}
+	return entries
+}
+
+// runFzfInteractive calls picker.Run and maps the chosen key to a PickerAction.
+func runFzfInteractive(ctx context.Context, entries []picker.Entry) (store.PickerResult, error) {
+	selection, err := picker.Run(ctx, entries)
+	if err != nil {
+		return store.PickerResult{}, err
+	}
+	action, ok := parsePickerAction(selection.Key)
+	if !ok || selection.Description == "" {
+		return store.PickerResult{}, nil
+	}
+	return store.PickerResult{
+		Description: selection.Description,
+		Action:      action,
+	}, nil
+}
+
+// parsePickerAction maps an fzf key string to a PickerAction.
+func parsePickerAction(keyLine string) (store.PickerAction, bool) {
+	switch strings.TrimSpace(keyLine) {
+	case "", "enter":
+		return store.PickerSelect, true
+	case "ctrl-t", "alt-t":
+		return store.PickerCat, true
+	case "ctrl-y", "alt-y":
+		return store.PickerPaste, true
+	case "ctrl-o", "alt-o":
+		return store.PickerOpen, true
+	case "ctrl-e", "alt-e":
+		return store.PickerEdit, true
+	default:
+		return "", false
+	}
+}