feat(console): add structured error handling, verbosity, and suggestions

Implement Phase 7.2 error handling & UX infrastructure:

- Add exit_code module with MozartError, bail()/bail_silent() helpers,
  and Composer-compatible exit code constants (0-5, 100)
- Redesign Console struct with Verbosity enum (Quiet/Normal/Verbose/
  VeryVerbose/Debug), ANSI auto-detection via IsTerminal, and
  verbosity-gated output methods (info/verbose/debug/error)
- Thread Console through all 33 command execute() signatures
- Replace all std::process::exit() calls with structured MozartError
  returns handled in main()
- Migrate eprintln\! status messages to console.info() for quiet-mode
  suppression
- Add suggest module with Levenshtein distance and "Did you mean?"
  formatting for future package name suggestions

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

1 files changed, 9 insertions, 5 deletions

diff --git a/crates/mozart/src/commands/clear_cache.rs b/crates/mozart/src/commands/clear_cache.rs
index 819ca9f..59baff3 100644
--- a/crates/mozart/src/commands/clear_cache.rs
+++ b/crates/mozart/src/commands/clear_cache.rs
@@ -8,7 +8,11 @@ pub struct ClearCacheArgs {
     pub gc: bool,
 }
 
-pub fn execute(args: &ClearCacheArgs, cli: &super::Cli) -> anyhow::Result<()> {
+pub fn execute(
+    args: &ClearCacheArgs,
+    cli: &super::Cli,
+    console: &crate::console::Console,
+) -> anyhow::Result<()> {
     let config = build_cache_config(cli);
 
     if args.gc {
@@ -19,8 +23,8 @@ pub fn execute(args: &ClearCacheArgs, cli: &super::Cli) -> anyhow::Result<()> {
         repo_cache.gc(config.cache_ttl, u64::MAX)?;
         files_cache.gc(config.cache_files_ttl, config.cache_files_maxsize)?;
 
-        eprintln!("Cache garbage collection complete.");
-        eprintln!("Cache directory: {}", config.cache_dir.display());
+        console.info("Cache garbage collection complete.");
+        console.info(&format!("Cache directory: {}", config.cache_dir.display()));
     } else {
         // Full clear of all cache directories
         let repo_cache = Cache::repo(&config);
@@ -44,8 +48,8 @@ pub fn execute(args: &ClearCacheArgs, cli: &super::Cli) -> anyhow::Result<()> {
             }
         }
 
-        eprintln!("Cache cleared.");
-        eprintln!("Cache directory: {}", config.cache_dir.display());
+        console.info("Cache cleared.");
+        console.info(&format!("Cache directory: {}", config.cache_dir.display()));
     }
 
     Ok(())