Fix test_parse_dep_atoms: strip version suffix after regex match

The regex required names to end with a letter ([a-zA-Z]) to avoid
capturing version numbers, but this rejected valid packages like
"nghttp2" that end with a digit.

Fix: use a greedy regex that captures the full "category/name-version"
string, then strip the version suffix with a dedicated function that
finds the last "-" followed by a digit. This correctly handles:
- "dev-libs/openssl-1.0.2" → "openssl"
- "net-libs/nghttp2" → "nghttp2" (no version, ends in digit)
- "sys-libs/zlib" → "zlib"
- "dev-qt/qt6-base-6.8.0" → "qt6-base" (hyphen in name)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/dpack/src/converter/gentoo.rs

@@ -321,11 +321,11 @@ fn parse_use_flags(iuse: &str) -> HashMap<String, OptionalDep> {
 /// Strips category prefixes and version constraints for dpack format.
 fn parse_dep_atoms(deps: &str, warnings: &mut ConversionWarnings) -> Vec<String> {
     let mut result = Vec::new();
-    // Regex to extract category/name from a single Gentoo atom token
+    // Regex to extract category/name from a single Gentoo atom token.
-    // Strips: leading operator (>=, <=, ~, =), trailing version (-1.2.3),
+    // After stripping slot/USE suffixes, match: [operator]category/name[-version]
-    //         slot (:0=), and USE flags ([foo,bar])
+    // The name capture grabs category/name, then we strip any trailing -<version>.
     let atom_re = Regex::new(
-        r"^(?:>=|<=|~|=)?([a-zA-Z0-9_-]+/[a-zA-Z0-9_+-]+[a-zA-Z])"
+        r"^(?:>=|<=|~|=)?([a-zA-Z0-9_-]+/[a-zA-Z0-9_.+-]+)"
     ).unwrap();
 
     // Process each whitespace-separated token, skipping non-atoms
@@ -358,13 +358,18 @@ fn parse_dep_atoms(deps: &str, warnings: &mut ConversionWarnings) -> Vec<String>
         if let Some(caps) = atom_re.captures(without_slot) {
             if let Some(m) = caps.get(1) {
                 let full_atom = m.as_str();
-                let pkg_name = full_atom
+
+                // Strip version suffix: find last "-" followed by a digit
+                // e.g., "dev-libs/openssl-1.0.2" → "dev-libs/openssl"
+                let cat_name = strip_version_suffix(full_atom);
+
+                let pkg_name = cat_name
                     .rsplit('/')
                     .next()
-                    .unwrap_or(full_atom)
+                    .unwrap_or(cat_name)
                     .to_string();
 
-                if full_atom.starts_with("virtual/") {
+                if cat_name.starts_with("virtual/") {
                     continue;
                 }
 
@@ -386,6 +391,22 @@ fn parse_dep_atoms(deps: &str, warnings: &mut ConversionWarnings) -> Vec<String>
     result
 }
 
+/// Strip the version suffix from a Gentoo atom.
+/// e.g., "dev-libs/openssl-1.0.2" → "dev-libs/openssl"
+///       "net-libs/nghttp2" → "net-libs/nghttp2" (no version, unchanged)
+///       "sys-libs/zlib" → "sys-libs/zlib"
+fn strip_version_suffix(atom: &str) -> &str {
+    // Find the last '-' that is followed by a digit — that's the version separator
+    // Must search from the end because package names can contain '-' (e.g., "qt6-base")
+    let bytes = atom.as_bytes();
+    for i in (0..bytes.len().saturating_sub(1)).rev() {
+        if bytes[i] == b'-' && bytes[i + 1].is_ascii_digit() {
+            return &atom[..i];
+        }
+    }
+    atom
+}
+
 /// Extract a phase function body (e.g., src_configure, src_install).
 fn extract_phase_function(content: &str, func_name: &str) -> String {
     let mut in_func = false;