feat: improve depot UX and packaging workflow

- add shared terminal UI helpers for colored info/warn/success logs and yes/no prompts
- add Python build backend (PEP 517/setup.py wheel build + install) and expose python in interactive spec creation
- expand spec/build flags (post_configure, make phase targets/dirs, configure_file, no_strip, no_compress_man)
- support split-output staging with internal .depot output dirs, shell helpers (haul/subdestdir), and per-output deps/provides overrides
- improve staging with ELF auto-strip and zstd manpage compression (with opt-out flags)
- enforce runtime deps before install and support legacy lifecycle hook script names
- improve manual source handling with files/urls lists and stricter validation

src/source/fetcher.rs

@@ -24,11 +24,11 @@ pub fn fetch_archive(spec: &PackageSpec, source: &Source, cache_dir: &Path) -> R
 
     // Check if already cached and verified
     if dest_path.exists() && verify_checksum(&dest_path, &source.sha256)? {
-        println!("Using cached source: {}", dest_path.display());
+        crate::log_info!("Using cached source: {}", dest_path.display());
         return Ok(dest_path);
     }
 
-    println!("Fetching: {}", url);
+    crate::log_info!("Fetching: {}", url);
 
     // Parse URL early so we can handle non-HTTP schemes (FTP support)
     let parsed_url = Url::parse(&url).with_context(|| format!("Invalid URL: {}", url))?;
@@ -165,7 +165,7 @@ pub fn fetch_archive(spec: &PackageSpec, source: &Source, cache_dir: &Path) -> R
         if !seen_alts.insert(alt.clone()) {
             bail!("Mirror retry loop detected for URL: {}", alt);
         }
-        println!("Retrying download from mirror: {}", alt);
+        crate::log_info!("Retrying download from mirror: {}", alt);
         fs::remove_file(&dest_path).ok();
 
         // If mirror URL is FTP -> use suppaftp; otherwise use HTTP retry.
@@ -280,7 +280,7 @@ pub fn fetch_archive(spec: &PackageSpec, source: &Source, cache_dir: &Path) -> R
         bail!("Checksum verification failed for {}", filename);
     }
 
-    println!("Checksum verified: {}", filename);
+    crate::log_info!("Checksum verified: {}", filename);
     Ok(dest_path)
 }