Port QConnect to self-contained prost implementation

Replaces qbz path-dependencies with a standalone implementation using
tokio-tungstenite and prost. Fixes queue-clear sentinel handling, pause
position reporting, track-end queue advancement, and adds periodic
position progress reports to keep the app progress bar in sync.

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

Cargo.lock

@@ -1602,6 +1602,29 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "prost"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2796faa41db3ec313a31f7624d9286acf277b52de526150b7e69f3debf891ee5"
+dependencies = [
+ "bytes",
+ "prost-derive",
+]
+
+[[package]]
+name = "prost-derive"
+version = "0.13.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a56d757972c98b346a9b766e3f02746cde6dd1cd1d1d563472929fdd74bec4d"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "qobuzd"
 version = "0.1.0"
@@ -1622,6 +1645,7 @@ dependencies = [
  "hmac",
  "keyring",
  "md-5",
+ "prost",
  "rand 0.8.5",
  "rand_chacha 0.3.1",
  "reqwest",
@@ -1932,7 +1956,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.61.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -1993,9 +2017,9 @@ dependencies = [
 
 [[package]]
 name = "schannel"
-version = "0.1.28"
+version = "0.1.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "891d81b926048e76efe18581bf793546b4c0eaf8448d72be8de2bbee5fd166e1"
+checksum = "91c1b7e4904c873ef0710c1f407dde2e6287de2bebc1bbbf7d430bb7cbffd939"
 dependencies = [
  "windows-sys 0.61.2",
 ]
@@ -2379,10 +2403,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
 dependencies = [
  "fastrand",
- "getrandom 0.4.2",
+ "getrandom 0.3.4",
  "once_cell",
  "rustix",
- "windows-sys 0.61.2",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]