feat(mix): add Elixir Mix command filter

src/discover/registry.rs

@@ -40,6 +40,7 @@ pub fn category_avg_tokens(category: &str, subcmd: &str) -> usize {
         "GitHub" => 200,
         "GitLab" => 200,
         "PackageManager" => 150,
+        "Elixir" => 400,
         _ => 150,
     }
 }

src/discover/rules.rs

@@ -521,6 +521,23 @@ pub const RULES: &[RtkRule] = &[
         subcmd_savings: &[],
         subcmd_status: &[],
     },
+    // Elixir tooling
+    RtkRule {
+        pattern: r"^mix\s+(test|compile|credo|phx\.routes|ash\.codegen|ash_postgres\.generate_migrations)",
+        rtk_cmd: "rtk mix",
+        rewrite_prefixes: &["mix"],
+        category: "Elixir",
+        savings_pct: 85.0,
+        subcmd_savings: &[
+            ("test", 90.0),
+            ("compile", 85.0),
+            ("credo", 80.0),
+            ("phx.routes", 70.0),
+            ("ash.codegen", 88.0),
+            ("ash_postgres.generate_migrations", 88.0),
+        ],
+        subcmd_status: &[],
+    },
     RtkRule {
         pattern: r"^aws\s+",
         rtk_cmd: "rtk aws",

src/main.rs

@@ -4,6 +4,7 @@ mod core;
 mod discover;
 mod hooks;
 mod learn;
+mod mix_cmd;
 mod parser;
 
 // Re-export command modules for routing
@@ -672,6 +673,13 @@ enum Commands {
         args: Vec<String>,
     },
 
+    /// Elixir Mix commands with compact output (compile, credo, phx.routes, ash.codegen)
+    Mix {
+        /// Mix arguments (e.g., compile, credo, phx.routes)
+        #[arg(trailing_var_arg = true, allow_hyphen_values = true)]
+        args: Vec<String>,
+    },
+
     /// Mypy type checker with grouped error output
     Mypy {
         /// Mypy arguments
@@ -2134,6 +2142,8 @@ fn run_cli() -> Result<i32> {
 
         Commands::Pytest { args } => pytest_cmd::run(&args, cli.verbose)?,
 
+        Commands::Mix { args } => mix_cmd::run(&args, cli.verbose)?,
+
         Commands::Mypy { args } => mypy_cmd::run(&args, cli.verbose)?,
 
         Commands::Rake { args } => rake_cmd::run(&args, cli.verbose)?,
@@ -2496,6 +2506,7 @@ fn is_operational_command(cmd: &Commands) -> bool {
             | Commands::Npm { .. }
             | Commands::Npx { .. }
             | Commands::Curl { .. }
+            | Commands::Mix { .. }
             | Commands::Ruff { .. }
             | Commands::Pytest { .. }
             | Commands::Rake { .. }