fix: sticky mux reconnect prevents USB port theft

Once the bridge connects via mux, all subsequent reconnects use mux-only
mode (connect_mux_auto). Previously, each reconnect re-ran the full
mux→USB fallback chain, which could steal the serial port from the mux
during a brief disconnect.

Cargo.lock

@@ -906,7 +906,7 @@ dependencies = [
 
 [[package]]
 name = "donglora-bridge"
-version = "0.3.0"
+version = "0.3.1"
 dependencies = [
  "anyhow",
  "blake3",
@@ -938,9 +938,9 @@ dependencies = [
 
 [[package]]
 name = "donglora-client"
-version = "0.2.0"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1936935d31ab56a8cd70ceecfd6d447f2628a73a123e1cfe37ee4987eab0fa70"
+checksum = "343d750fe1e5dad94d4b31e6dbbb05214b39e66f3c94a2ff2a29b0031ffd2826"
 dependencies = [
  "anyhow",
  "serialport",
@@ -1071,9 +1071,9 @@ dependencies = [
 
 [[package]]
 name = "fastrand"
-version = "2.4.0"
+version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a043dc74da1e37d6afe657061213aa6f425f855399a11d3463c6ecccc4dfda1f"
+checksum = "9f1f227452a390804cdb637b74a86990f2a7d7ba4b7d5693aac9b4dd6defd8d6"
 
 [[package]]
 name = "fiat-crypto"
@@ -4358,9 +4358,9 @@ dependencies = [
 
 [[package]]
 name = "toml_edit"
-version = "0.25.10+spec-1.1.0"
+version = "0.25.11+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a82418ca169e235e6c399a84e395ab6debeb3bc90edc959bf0f48647c6a32d1b"
+checksum = "0b59c4d22ed448339746c59b905d24568fcbb3ab65a500494f7b8c3e97739f2b"
 dependencies = [
  "indexmap",
  "toml_datetime",