[refactor](trx-rs): adopt shared app infra modules

Phase 4: route config loading and plugin discovery through trx-app, remove duplicated local plugin loaders, and align binary dependencies.

Co-authored-by: Codex <codex@openai.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-server/Cargo.toml

@@ -14,10 +14,8 @@ serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 toml = { workspace = true }
 tracing = { workspace = true }
-tracing-subscriber = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 dirs = "6"
-libloading = "0.8"
 bytes = "1"
 cpal = "0.15"
 opus = "0.3"