feat!: wishlist, upload-queue privilege recognition, and search filters (#20)

Closes the last two gaps in Soulseek's list of features an alternative client
must implement to be tolerated, and adds the result filters Nicotine+ has had
all along.

Wishlist: server code 103 is sent and code 104's announced interval is kept
rather than logged and discarded, so the re-search timer runs off the schedule
the server set. `wish add|remove|list|run` plus `serve --wishlist`; wishes
persist in config.toml as a TOML array so a comma inside a query survives.
`wish run` prints search-shaped records, so it pipes into `download --stdin`.

Privilege recognition: the code-69 user list is parsed instead of counted and
dropped, and code 92 answers `whoami` as `privilege_seconds`. Uploads now go
through a queue with a slot cap (`--upload-slots`, default 2) that serves
privileged users first — the cap is what makes the ordering mean anything, so
they are one change. `PlaceInQueueRequest` (peer code 51) is answered, where it
previously had no handler at all, and a departed peer's slot is released so a
stalled peer cannot wedge uploads shut.

Search filters: `--exclude`, `--extension`, `--min-size`, `--max-size` beside
the existing `--min-bitrate` and `--free-slots`, in one flattened arg group
shared by `search`, `get` and `wish run`.

Also serialises the library e2e suite behind the same gate `cli_e2e` already
uses: the new queue tests hold peer sockets open on purpose, which starved
concurrently-spawned soulfinds and failed unrelated download tests with
`login: Timeout`.

BREAKING CHANGE: `UploadStatus` gains a `Queued(u32)` variant, so an exhaustive
match on it no longer compiles, and `cli::Commands` gains `Wish`.

soulseek-rs/src/commands/mod.rs

@@ -11,6 +11,7 @@ pub mod settings;
 pub mod skills;
 pub mod social;
 pub mod transfer;
+pub mod wish;
 
 use crate::cli::{Commands, MessageCommand, RoomCommand};
 use crate::output::{CliError, CliResult, Exit, Out, PortmapRecord};
@@ -191,13 +192,16 @@ pub fn run(ctx: &Ctx, command: Commands) -> CliResult {
         Commands::Message(MessageCommand::Read { duration, follow }) => {
             social::message_read(ctx, listen_span(duration, follow))
         }
-        Commands::Serve(args) => peer::serve(ctx, &args),
         Commands::User(args) => peer::user(ctx, &args),
         Commands::Whoami => peer::whoami(ctx),
         // These need no account, so main.rs answers them before asking for
         // credentials; the arms exist only to keep the match exhaustive.
         Commands::Portmap => portmap(&ctx.out, ctx.settings.listen_port),
-        Commands::Config(_)
+        // These need the config file as well as a session, so main.rs runs
+        // them where the store is in scope.
+        Commands::Serve(_)
+        | Commands::Wish(_)
+        | Commands::Config(_)
         | Commands::Shares(_)
         | Commands::Skills(_)
         | Commands::Completions(_) => {