Client::set_shared_directories rescans the given roots into a fresh
in-memory index, swaps it for peers, and re-announces the folder/file
counts to the server. The current directory list moves into the client
context so the running set is queryable. e2e-verified: a browser sees a
directory that was added after login.
Shares::scan_many merges several roots into one index, suffixing
duplicate root names so virtual paths cannot collide, and skipping
unreadable roots instead of failing. ClientSettings now takes
shared_directories: Vec<String>; config gains a shared_dirs list
(combined with the single shared_dir and --shared-dir, deduped), with an
explicitly empty value still disabling sharing and the
share-what-you-download default unchanged.
GetShareFileList (peer code 4) previously replied with a malformed message (a
server SharedFolders stats message over a peer connection). It now emits
ShareListRequested, and the client builds a real SharedFileListResponse
(code 5) from its shares grouped by directory. Adds a std-only code-5
encoder/decoder (build_shared_file_list / parse_shared_file_list) with a
roundtrip test, and Shares::directories() to group files. The decoder is the
foundation for the Browse feature.
Add a std-only shares module: Shares::scan walks the shared directory (skipping
symlinks and unreadable entries) into a read-only snapshot keyed by peer-facing
virtual path (root name + backslash-separated relative path). Exposes
search (case-insensitive multi-term AND), get (O(1) by virtual path), and
file/folder counts for the login handshake. Unit-tested against a temp tree.
michel