refactor(maestro): one default-on-missing config loader

load() and load_or_default() differed only in whether a missing file was
an error. Nothing wants the error: every field has a default. Keeps
load(), drops the MissingFile variant, whose message pointed at the
`maestro daemon configure` subcommand the single-host refactor deleted.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

crates/maestro-cli/src/config.rs

@@ -45,7 +45,7 @@ impl CliConfig {
     /// Load the subset of the unified file the CLI consumes. A missing file is
     /// fine — every field has a default.
     pub fn load(path: &Path) -> Result<Self, ConfigError> {
-        let file = MaestroConfigFile::load_or_default(path)?;
+        let file = MaestroConfigFile::load(path)?;
         Ok(Self {
             daemon_url: file.cli.daemon_url,
             daemon_bind_addr: file.daemon.bind_addr,

crates/maestro-config/src/lib.rs

@@ -41,12 +41,6 @@ pub enum ConfigError {
     TomlEncode(#[from] toml::ser::Error),
     #[error("could not determine config directory (XDG_CONFIG_HOME / $HOME unset?)")]
     NoConfigDir,
-    #[error(
-        "maestro config not found at {}\n\
-         Run `maestro daemon configure` to create it.",
-        path.display()
-    )]
-    MissingFile { path: PathBuf },
     #[error("invalid {env} ({input:?}): {source}")]
     InvalidBindAddr {
         env: &'static str,
@@ -314,27 +308,17 @@ fn validate_presets(presets: &[SpawnPreset]) -> Result<(), SpawnConfigError> {
 }
 
 impl MaestroConfigFile {
-    /// Strict load — error with [`ConfigError::MissingFile`] if absent.
+    /// Load the file, or return an empty config if it doesn't exist. Every
+    /// field has a default, so a missing file is never an error.
     pub fn load(path: &Path) -> Result<Self, ConfigError> {
         if !path.exists() {
-            return Err(ConfigError::MissingFile {
-                path: path.to_path_buf(),
-            });
+            return Ok(Self::default());
         }
         let bytes = std::fs::read(path)?;
         let s = std::str::from_utf8(&bytes).unwrap_or("");
         Ok(toml::from_str(s)?)
     }
 
-    /// Load if present, else return an empty config. Use for callers that
-    /// want a default-on-missing read.
-    pub fn load_or_default(path: &Path) -> Result<Self, ConfigError> {
-        if !path.exists() {
-            return Ok(Self::default());
-        }
-        Self::load(path)
-    }
-
     /// Atomic write (tmp + rename). Creates parent dirs on demand.
     pub fn save(&self, path: &Path) -> Result<(), ConfigError> {
         if let Some(parent) = path.parent() {
@@ -447,20 +431,10 @@ mod tests {
     }
 
     #[test]
-    fn missing_file_strict_load_errors_with_pointer_to_configure() {
+    fn missing_file_loads_as_empty_config() {
         let dir = tempfile::tempdir().unwrap();
         let path = dir.path().join("config.toml");
-        let err = MaestroConfigFile::load(&path).unwrap_err();
-        let msg = err.to_string();
-        assert!(matches!(err, ConfigError::MissingFile { .. }));
-        assert!(msg.contains("maestro daemon configure"), "msg was: {msg}");
-    }
-
-    #[test]
-    fn missing_file_load_or_default_returns_empty() {
-        let dir = tempfile::tempdir().unwrap();
-        let path = dir.path().join("config.toml");
-        let cfg = MaestroConfigFile::load_or_default(&path).unwrap();
+        let cfg = MaestroConfigFile::load(&path).unwrap();
         assert_eq!(cfg, MaestroConfigFile::default());
     }
 

crates/maestro-daemon/src/config.rs

@@ -111,7 +111,7 @@ impl EnvOverrides {
 /// Resolve the runtime configuration: env overrides on top of the unified
 /// file, then defaults. A missing file is not an error.
 pub fn load_config(path: &Path, env: EnvOverrides) -> Result<DaemonConfig, ConfigError> {
-    let file = MaestroConfigFile::load_or_default(path)?;
+    let file = MaestroConfigFile::load(path)?;
 
     let daemon = file.daemon;
     // Resolve spawn presets up front so a bad `[spawn].presets` (empty/dup id,

crates/maestro-tui/src/lib.rs

@@ -1,7 +1,4 @@
 //! `maestro tui` — terminal UI client over the local daemon's `/api/*` surface.
-//!
-//! Design:         `docs/superpowers/specs/2026-05-28-maestro-tui-design.md`
-//! Implementation: `docs/superpowers/plans/2026-05-28-maestro-tui.md`
 
 #![deny(missing_debug_implementations)]
 
@@ -74,7 +71,7 @@ pub async fn run(cfg: RunConfig) -> Result<(), TuiError> {
         maestro_config::resolve_config_path().map_err(|e| TuiError::Config(e.to_string()))
     });
     let cfg_file = match cfg_path {
-        Ok(path) => maestro_config::MaestroConfigFile::load_or_default(&path)
+        Ok(path) => maestro_config::MaestroConfigFile::load(&path)
             .map_err(|e| TuiError::Config(e.to_string()))?,
         Err(_) => maestro_config::MaestroConfigFile::default(),
     };

crates/maestro-web/src/config.rs

@@ -59,11 +59,7 @@ impl EnvOverrides {
 /// Resolve the runtime configuration. Missing-file is fine: every field has
 /// a default and the binary is happy to run with no config.toml at all.
 pub fn load_config(path: &Path, env: EnvOverrides) -> Result<WebConfig, WebConfigError> {
-    let file = if path.exists() {
-        MaestroConfigFile::load(path)?
-    } else {
-        MaestroConfigFile::default()
-    };
+    let file = MaestroConfigFile::load(path)?;
     resolve_with(file.web, env)
 }