Rename project: battlenet-manager → umutray

Binary, crate, clap app name, ksni tray id, HTTP user-agent, systemd unit,
XDG config dir (co.aleshym/umutray), README, and all log prefixes.

Config path changes from ~/.config/battlenet-manager/ to ~/.config/umutray/.
Existing users should `mv` the old directory if they've customised it;
otherwise defaults get rewritten on next run.

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

Cargo.lock

@@ -90,20 +90,6 @@ version = "0.22.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b3254f16251a8381aa12e40e3c4d2f0199f8c6508fbecb9d91f575e0fbb8c6"
 
-[[package]]
-name = "battlenet-manager"
-version = "0.1.0"
-dependencies = [
- "anyhow",
- "clap 4.6.1",
- "directories",
- "ksni",
- "reqwest",
- "serde",
- "serde_json",
- "toml",
-]
-
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -1530,6 +1516,20 @@ version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e421abadd41a4225275504ea4d6566923418b7f05506fbc9c0fe86ba7396114b"
 
+[[package]]
+name = "umutray"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "clap 4.6.1",
+ "directories",
+ "ksni",
+ "reqwest",
+ "serde",
+ "serde_json",
+ "toml",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"