feat: persistent multi-share configuration (shares.json + localStorage)

Daemon side:
- internal/shares: new package reads/writes shares.json next to identity
- proto: add ShareEntry type, add_share/remove_share/list_shares IPC commands,
  shares_list event, path field on FileEntry
- netmgr: load shares.json on startup; ScanAllShares combines legacy ShareDir
  with shares.json entries (recursive walk with relative paths)
- mesh: ScanFiles callback lets manager inject multi-share scanning without
  mesh knowing about shares.json
- ipc: handle add_share, remove_share, list_shares commands

Browser side:
- ShareManager component replaces FolderPicker: shows list of named shares
  with remove/re-pick buttons; persists share records to waste_shares in
  localStorage (name, global flag, networkId)
- FolderPicker retained for internal use; Sidebar now uses ShareManager

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

internal/ipc/ipc.go

@@ -23,6 +23,7 @@ import (
 	"github.com/waste-go/internal/invite"
 	"github.com/waste-go/internal/netmgr"
 	"github.com/waste-go/internal/proto"
+	"github.com/waste-go/internal/shares"
 )
 
 // RunWS starts a WebSocket IPC server on 127.0.0.1:wsPort.
@@ -246,7 +247,7 @@ func handleClient(conn net.Conn, mgr *netmgr.Manager) {
 					Type:      proto.EvtFileList,
 					NetworkID: n.ID,
 					PeerID:    ptr(n.Identity.PeerID()),
-					Files:     n.Mesh.ScanShareDir(),
+					Files:     mgr.ScanAllShares(n.ID),
 				})
 			} else {
 				req, err := json.Marshal(proto.PeerMessage{Type: proto.MsgFileListReq})
@@ -258,6 +259,35 @@ func handleClient(conn net.Conn, mgr *netmgr.Manager) {
 				}
 			}
 
+		case proto.CmdAddShare:
+			if cmd.Path == "" {
+				send(errMsg("add_share: path is required"))
+				continue
+			}
+			networks := cmd.ShareNetworks
+			if len(networks) == 0 {
+				networks = []string{"*"}
+			}
+			if err := mgr.Shares.Add(shares.Share{Path: cmd.Path, Networks: networks}); err != nil {
+				send(errMsg(fmt.Sprintf("add_share: %v", err)))
+				continue
+			}
+			send(sharesListMsg(mgr))
+
+		case proto.CmdRemoveShare:
+			if cmd.Path == "" {
+				send(errMsg("remove_share: path is required"))
+				continue
+			}
+			if err := mgr.Shares.Remove(cmd.Path); err != nil {
+				send(errMsg(fmt.Sprintf("remove_share: %v", err)))
+				continue
+			}
+			send(sharesListMsg(mgr))
+
+		case proto.CmdListShares:
+			send(sharesListMsg(mgr))
+
 		case proto.CmdGenerateInvite:
 			n := mgr.Resolve(cmd.NetworkID)
 			if n == nil {
@@ -389,6 +419,18 @@ func errMsg(s string) proto.IpcMessage {
 	return proto.IpcMessage{Type: proto.EvtError, ErrorMessage: s}
 }
 
+func sharesListMsg(mgr *netmgr.Manager) proto.IpcMessage {
+	all := mgr.Shares.All()
+	entries := make([]proto.ShareEntry, len(all))
+	for i, sh := range all {
+		entries[i] = proto.ShareEntry{Path: sh.Path, Networks: sh.Networks}
+	}
+	return proto.IpcMessage{Type: proto.EvtSharesList, Shares: entries}
+}
+
+// ensure shares import is used
+var _ = shares.Share{}
+
 func ptr[T any](v T) *T { return &v }
 
 func randomHex(n int) string {

internal/mesh/mesh.go

@@ -29,6 +29,9 @@ type Mesh struct {
 	Store       *store.Store // may be nil if persistence is disabled
 	ShareDir    string       // directory whose contents are shared with peers; "" = no sharing
 	DownloadDir string       // directory where received files are saved
+	// ScanFiles overrides ScanShareDir when set — allows the manager to inject
+	// multi-share scanning without the mesh needing to know about shares.json.
+	ScanFiles func() []proto.FileEntry
 
 	mu    sync.RWMutex
 	peers map[proto.PeerID]*PeerConn

internal/mesh/peer.go

@@ -201,7 +201,12 @@ func dispatchPeerMessage(msg proto.PeerMessage, from proto.PeerID, m *Mesh) {
 		m.Emit(proto.IpcMessage{Type: proto.EvtMessageReceived, Message: chat})
 
 	case proto.MsgFileListReq:
-		files := m.ScanShareDir()
+		var files []proto.FileEntry
+		if m.ScanFiles != nil {
+			files = m.ScanFiles()
+		} else {
+			files = m.ScanShareDir()
+		}
 		resp, err := json.Marshal(proto.PeerMessage{
 			Type:         proto.MsgFileListResp,
 			FileListResp: &proto.FileListResp{Files: files},

internal/netmgr/manager.go

@@ -10,6 +10,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"log"
+	"os"
 	"path/filepath"
 	"sync"
 
@@ -17,6 +18,7 @@ import (
 	"github.com/waste-go/internal/crypto"
 	"github.com/waste-go/internal/mesh"
 	"github.com/waste-go/internal/proto"
+	"github.com/waste-go/internal/shares"
 	"github.com/waste-go/internal/store"
 )
 
@@ -54,13 +56,22 @@ type Manager struct {
 
 	subsMu sync.Mutex
 	subs   []chan proto.IpcMessage
+
+	Shares *shares.Store // persistent multi-share configuration
 }
 
 // New creates a Manager from the given config.
+// Loads shares.json from StoreDir if it exists.
 func New(cfg Config) *Manager {
+	sh, err := shares.Load(cfg.StoreDir)
+	if err != nil {
+		log.Printf("netmgr: loading shares.json: %v (starting empty)", err)
+		sh, _ = shares.Load("") // fallback to empty
+	}
 	return &Manager{
 		networks: make(map[string]*Network),
 		cfg:      cfg,
+		Shares:   sh,
 	}
 }
 
@@ -100,6 +111,8 @@ func (mgr *Manager) Join(name, shareDir string) (string, error) {
 		m.ShareDir = mgr.cfg.ShareDir
 	}
 	m.DownloadDir = filepath.Join(mgr.cfg.StoreDir, "downloads-"+netID_full)
+	capturedNetID := netID
+	m.ScanFiles = func() []proto.FileEntry { return mgr.ScanAllShares(capturedNetID) }
 
 	// Forward all mesh events to the Manager's fan-out, tagging with network_id.
 	meshEvents := m.Subscribe()
@@ -183,6 +196,8 @@ func (mgr *Manager) JoinByHash(netHash64, shareDir string) (string, error) {
 		m.ShareDir = mgr.cfg.ShareDir
 	}
 	m.DownloadDir = filepath.Join(mgr.cfg.StoreDir, "downloads-"+netID)
+	capturedNetID2 := netID
+	m.ScanFiles = func() []proto.FileEntry { return mgr.ScanAllShares(capturedNetID2) }
 
 	meshEvents := m.Subscribe()
 	go func() {
@@ -313,6 +328,50 @@ func (mgr *Manager) All() []*Network {
 	return out
 }
 
+// ScanAllShares returns file entries from all share roots visible to networkID,
+// combining the network's legacy ShareDir with entries from shares.json.
+func (mgr *Manager) ScanAllShares(netID string) []proto.FileEntry {
+	var files []proto.FileEntry
+
+	// Legacy single-dir share from the network mesh.
+	if n := mgr.Resolve(netID); n != nil {
+		files = append(files, n.Mesh.ScanShareDir()...)
+	}
+
+	// Additional shares from shares.json.
+	if mgr.Shares != nil {
+		for _, sh := range mgr.Shares.ForNetwork(netID) {
+			files = append(files, scanDir(sh.Path)...)
+		}
+	}
+	return files
+}
+
+// scanDir recursively walks a directory and returns FileEntry for each file.
+func scanDir(root string) []proto.FileEntry {
+	var files []proto.FileEntry
+	_ = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
+		if err != nil || d.IsDir() {
+			return nil
+		}
+		info, err := d.Info()
+		if err != nil {
+			return nil
+		}
+		rel, err := filepath.Rel(root, path)
+		if err != nil {
+			rel = d.Name()
+		}
+		files = append(files, proto.FileEntry{
+			Name:      d.Name(),
+			SizeBytes: info.Size(),
+			Path:      rel,
+		})
+		return nil
+	})
+	return files
+}
+
 // AnchorURL returns the configured anchor URL.
 func (mgr *Manager) AnchorURL() string { return mgr.cfg.AnchorURL }
 

internal/proto/proto.go

@@ -111,6 +111,13 @@ type GossipEntry struct {
 type FileEntry struct {
 	Name      string `json:"name"`
 	SizeBytes int64  `json:"size_bytes"`
+	Path      string `json:"path,omitempty"` // relative path including filename
+}
+
+// ShareEntry describes one persistent share root.
+type ShareEntry struct {
+	Path     string   `json:"path"`
+	Networks []string `json:"networks"` // ["*"] = global
 }
 
 // FileListResp is the payload for MsgFileListResp.
@@ -222,6 +229,9 @@ const (
 	CmdGetFileList    IpcMsgType = "get_file_list"
 	CmdExportIdentity IpcMsgType = "export_identity"  // returns encrypted backup blob
 	CmdImportIdentity IpcMsgType = "import_identity"  // replaces identity from backup blob
+	CmdAddShare       IpcMsgType = "add_share"        // add a share root; fields: path, networks
+	CmdRemoveShare    IpcMsgType = "remove_share"      // remove a share root; field: path
+	CmdListShares     IpcMsgType = "list_shares"       // returns shares_list event
 
 	// Events (daemon → UI)
 	EvtMessageReceived  IpcMsgType = "message_received"
@@ -240,6 +250,7 @@ const (
 	EvtNetworkLeft      IpcMsgType = "network_left"
 	EvtIdentityExported IpcMsgType = "identity_exported"
 	EvtIdentityImported IpcMsgType = "identity_imported"
+	EvtSharesList       IpcMsgType = "shares_list"
 )
 
 // NetworkInfo summarises one joined network for state_snapshot and network_joined events.
@@ -292,6 +303,8 @@ type IpcMessage struct {
 	ErrorMessage   string       `json:"error_message,omitempty"`
 	InviteString   string       `json:"invite,omitempty"`
 	Files          []FileEntry  `json:"files,omitempty"`
+	Shares         []ShareEntry `json:"shares,omitempty"`
+	ShareNetworks  []string     `json:"networks,omitempty"` // for add_share command
 	// export_identity / import_identity
 	Passphrase     string       `json:"passphrase,omitempty"` // import only; never echoed back
 	Backup         string       `json:"backup,omitempty"`     // JSON backup blob

internal/shares/shares.go

@@ -0,0 +1,99 @@
+// Package shares manages the persistent multi-share configuration stored in shares.json.
+// Shares are additive to the existing single-dir ShareDir mechanism.
+package shares
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sync"
+)
+
+// Share describes one shared directory entry.
+type Share struct {
+	Path     string   `json:"path"`
+	Networks []string `json:"networks"` // ["*"] = global (all networks); otherwise list of network IDs
+}
+
+// Store manages the shares.json file.
+type Store struct {
+	mu     sync.RWMutex
+	path   string
+	shares []Share
+}
+
+// Load reads shares.json from dataDir. Returns an empty store if the file doesn't exist.
+func Load(dataDir string) (*Store, error) {
+	s := &Store{path: filepath.Join(dataDir, "shares.json")}
+	data, err := os.ReadFile(s.path)
+	if os.IsNotExist(err) {
+		return s, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	if err := json.Unmarshal(data, &s.shares); err != nil {
+		return nil, err
+	}
+	return s, nil
+}
+
+func (s *Store) save() error {
+	data, err := json.MarshalIndent(s.shares, "", "  ")
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(s.path, data, 0600)
+}
+
+// All returns a copy of all shares.
+func (s *Store) All() []Share {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	out := make([]Share, len(s.shares))
+	copy(out, s.shares)
+	return out
+}
+
+// ForNetwork returns all shares visible on networkID (global + network-specific).
+func (s *Store) ForNetwork(networkID string) []Share {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	var out []Share
+	for _, sh := range s.shares {
+		for _, n := range sh.Networks {
+			if n == "*" || n == networkID {
+				out = append(out, sh)
+				break
+			}
+		}
+	}
+	return out
+}
+
+// Add adds a share (no-op if path already present). Persists immediately.
+func (s *Store) Add(sh Share) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for i, existing := range s.shares {
+		if existing.Path == sh.Path {
+			s.shares[i].Networks = sh.Networks
+			return s.save()
+		}
+	}
+	s.shares = append(s.shares, sh)
+	return s.save()
+}
+
+// Remove removes the share with the given path. Persists immediately.
+func (s *Store) Remove(path string) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	for i, sh := range s.shares {
+		if sh.Path == path {
+			s.shares = append(s.shares[:i], s.shares[i+1:]...)
+			return s.save()
+		}
+	}
+	return nil
+}