refactor(show): make format field non-optional with default "text"

Replace `Option<String>` with `String` + `default_value = "text"` and
derive `Default` on `ShowArgs`, eliminating local `as_deref().unwrap_or`
bindings. outdated.rs switches to `..Default::default()` for the fields
it doesn't set.

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

2 files changed, 13 insertions, 35 deletions

diff --git a/crates/mozart/src/commands/outdated.rs b/crates/mozart/src/commands/outdated.rs
index c17360d..12646f4 100644
--- a/crates/mozart/src/commands/outdated.rs
+++ b/crates/mozart/src/commands/outdated.rs
@@ -58,11 +58,7 @@ pub struct OutdatedArgs {
     pub ignore_platform_reqs: bool,
 }
 
-/// `outdated` is a proxy command — it mirrors Composer's `OutdatedCommand::execute`
-/// (see `composer/src/Composer/Command/OutdatedCommand.php` 68–126), which remaps
-/// its options into a `show --latest [--outdated]` invocation. Keeping the logic
-/// in one place means every behavioral aspect (rendering, JSON shape, --strict,
-/// mutual-exclusion checks, ignore warnings, etc.) has a single source of truth.
+/// `outdated` is a proxy command, forwarding to `show --latest`.
 pub async fn execute(
     args: &OutdatedArgs,
     cli: &super::Cli,
@@ -70,18 +66,8 @@ pub async fn execute(
 ) -> anyhow::Result<()> {
     let show_args = super::show::ShowArgs {
         package: args.package.clone(),
-        version: None,
-        all: false,
         locked: args.locked,
-        installed: false,
-        platform: false,
-        available: false,
-        self_info: false,
-        name_only: false,
-        path: false,
-        tree: false,
         latest: true,
-        // Composer: `if (!--all) $args['--outdated'] = true;`
         outdated: !args.all,
         ignore: args.ignore.clone(),
         major_only: args.major_only,
@@ -90,10 +76,11 @@ pub async fn execute(
         sort_by_age: args.sort_by_age,
         direct: args.direct,
         strict: args.strict,
-        format: Some(args.format.clone()),
+        format: args.format.clone(),
         no_dev: args.no_dev,
         ignore_platform_req: args.ignore_platform_req.clone(),
         ignore_platform_reqs: args.ignore_platform_reqs,
+        ..Default::default()
     };
 
     super::show::execute(&show_args, cli, console).await
diff --git a/crates/mozart/src/commands/show.rs b/crates/mozart/src/commands/show.rs
index 6a07fb0..f0b82b3 100644
--- a/crates/mozart/src/commands/show.rs
+++ b/crates/mozart/src/commands/show.rs
@@ -8,7 +8,7 @@ use mozart_core::platform::is_platform_package;
 use std::collections::BTreeMap;
 use std::path::Path;
 
-#[derive(Args)]
+#[derive(Default, Args)]
 pub struct ShowArgs {
     /// Package to inspect
     pub package: Option<String>,
@@ -89,8 +89,8 @@ pub struct ShowArgs {
     pub strict: bool,
 
     /// Output format (text, json)
-    #[arg(short, long)]
-    pub format: Option<String>,
+    #[arg(short, long, default_value = "text")]
+    pub format: String,
 
     /// Disables listing of require-dev packages
     #[arg(long)]
@@ -152,13 +152,10 @@ pub async fn execute(
     }
 
     // --format validation
-    if let Some(ref fmt) = args.format
-        && fmt != "text"
-        && fmt != "json"
-    {
+    if args.format != "text" && args.format != "json" {
         anyhow::bail!(
             "Unsupported format \"{}\". See help for supported formats.",
-            fmt
+            args.format
         );
     }
 
@@ -539,7 +536,6 @@ fn render_package_list(
     console: &mozart_core::console::Console,
 ) -> anyhow::Result<bool> {
     let show_latest = args.latest || args.outdated;
-    let format = args.format.as_deref().unwrap_or("text");
 
     // A4: --sort-by-age (mirrors Composer 497-504)
     if args.sort_by_age {
@@ -548,7 +544,7 @@ fn render_package_list(
 
     let has_outdated = entries.iter().any(|e| e.latest_info.is_some());
 
-    if format == "json" {
+    if args.format == "json" {
         render_list_json(entries, section_key, console)?;
         return Ok(has_outdated);
     }
@@ -934,8 +930,7 @@ async fn print_package_detail(
     repo_cache: &mozart_registry::cache::Cache,
     console: &mozart_core::console::Console,
 ) -> anyhow::Result<()> {
-    let format = args.format.as_deref().unwrap_or("text");
-    if format == "json" {
+    if args.format == "json" {
         return print_package_detail_json(detail, args, repo_cache, console).await;
     }
 
@@ -1777,8 +1772,7 @@ fn show_platform(
 
     platform_packages.sort_by(|a, b| a.0.cmp(&b.0));
 
-    let format = args.format.as_deref().unwrap_or("text");
-    if format == "json" {
+    if args.format == "json" {
         let json_entries: Vec<serde_json::Value> = platform_packages
             .iter()
             .map(|(name, version, source)| {
@@ -1898,9 +1892,7 @@ async fn show_available(
     );
     console_writeln!(console, "");
 
-    let format = args.format.as_deref().unwrap_or("text");
-
-    if format == "json" {
+    if args.format == "json" {
         let mut json_entries: Vec<serde_json::Value> = Vec::new();
         for pkg in &installed.packages {
             if is_platform_package(&pkg.name) {
@@ -1952,8 +1944,7 @@ async fn show_available_versions(
         return Ok(());
     }
 
-    let format = args.format.as_deref().unwrap_or("text");
-    if format == "json" {
+    if args.format == "json" {
         let version_strings: Vec<String> = versions.iter().map(|v| v.version.clone()).collect();
         let output = serde_json::json!({
             "name": pkg_name,