Fixes calculations (#2)

Git Level (per commit):
    - Track unique file paths in FilesModified slice
    - FilesChanged = count of unique files in THIS commit

  Aggregator Level (per contributor):
    - Collect all file paths from all commits into a SET
    - FilesChanged = size of the unique file set

  Result:
    - Contributor.FilesChanged = count of UNIQUE files they touched
    - Repository contributor = unique files in THAT repo only

internal/diff/analyzer.go

@@ -5,19 +5,22 @@ import (
 )
 
 // IsCommentLine checks if a line is a code comment (should not count as meaningful contribution)
+// Note: Empty/whitespace lines are NOT comments - use IsWhitespaceLine for those.
 func IsCommentLine(line string) bool {
 	trimmed := strings.TrimSpace(line)
 	if trimmed == "" {
-		return true // Empty lines don't count
+		return false // Empty lines are whitespace, not comments
 	}
 
 	// Common comment patterns across languages
+	// Order matters for overlapping prefixes (e.g., "///" before "//")
 	commentPrefixes := []string{
+		"///",    // Rust/Swift/C# doc comments
 		"//",     // C, C++, Java, Go, JS, TS, Swift, Kotlin, etc.
 		"#",      // Python, Ruby, Shell, YAML, Perl, etc.
+		"/**",    // JSDoc/JavaDoc block start
 		"/*",     // C-style block comment start
 		"*/",     // C-style block comment end
-		"*",      // C-style block comment continuation
 		"<!--",   // HTML/XML comment
 		"-->",    // HTML/XML comment end
 		"--",     // SQL, Lua, Haskell
@@ -33,6 +36,19 @@ func IsCommentLine(line string) bool {
 		}
 	}
 
+	// C-style block comment continuation: line starts with * followed by space or end of line
+	// This avoids false positives like "*ptr = value" (pointer dereference)
+	if strings.HasPrefix(trimmed, "*") {
+		if len(trimmed) == 1 {
+			return true // Just "*" alone
+		}
+		// Must be followed by whitespace or common comment characters, not alphanumeric
+		nextChar := trimmed[1]
+		if nextChar == ' ' || nextChar == '\t' || nextChar == '/' {
+			return true
+		}
+	}
+
 	return false
 }
 
@@ -64,6 +80,96 @@ func IsMeaningfulLine(line string) bool {
 	return !IsWhitespaceLine(line) && !IsCommentLine(line)
 }
 
+// IsDocCommentLine checks if a line is a documentation comment (JSDoc, JavaDoc, Rust doc, etc.)
+// These are comments specifically meant to document code, as opposed to regular comments.
+func IsDocCommentLine(line string) bool {
+	trimmed := strings.TrimSpace(line)
+	if trimmed == "" {
+		return false
+	}
+
+	// Documentation comment patterns
+	docPrefixes := []string{
+		"///",    // Rust, Swift, C# doc comments
+		"//!",    // Rust inner doc comments
+		"/**",    // JSDoc, JavaDoc block start
+		"\"\"\"", // Python docstring
+		"'''",    // Python docstring
+	}
+
+	for _, prefix := range docPrefixes {
+		if strings.HasPrefix(trimmed, prefix) {
+			return true
+		}
+	}
+
+	// JSDoc/JavaDoc continuation lines with annotations (@param, @return, etc.)
+	if strings.HasPrefix(trimmed, "* @") || strings.HasPrefix(trimmed, "*  @") {
+		return true
+	}
+
+	// Check for common doc annotations at the start of a comment
+	if strings.HasPrefix(trimmed, "// @") || strings.HasPrefix(trimmed, "# @") {
+		return true
+	}
+
+	return false
+}
+
+// IsCommentedOutCode attempts to detect if a comment line contains commented-out code
+// rather than an actual comment. This is a heuristic and may have false positives/negatives.
+func IsCommentedOutCode(line string) bool {
+	trimmed := strings.TrimSpace(line)
+	if trimmed == "" {
+		return false
+	}
+
+	// Remove comment prefix to get the content
+	var content string
+	commentPrefixes := []string{"///", "//", "#", "/*", "--", ";"}
+	for _, prefix := range commentPrefixes {
+		if strings.HasPrefix(trimmed, prefix) {
+			content = strings.TrimSpace(trimmed[len(prefix):])
+			break
+		}
+	}
+
+	if content == "" {
+		return false
+	}
+
+	// Heuristics for detecting commented-out code:
+	// 1. Ends with common code patterns
+	codeEndings := []string{";", "{", "}", ")", ",", ":", "=>", "->"}
+	for _, ending := range codeEndings {
+		if strings.HasSuffix(content, ending) {
+			return true
+		}
+	}
+
+	// 2. Starts with common code keywords
+	codeKeywords := []string{
+		"if ", "else ", "for ", "while ", "switch ", "case ", "return ", "break", "continue",
+		"const ", "let ", "var ", "func ", "function ", "def ", "class ", "struct ", "type ",
+		"import ", "from ", "package ", "public ", "private ", "protected ", "static ",
+		"async ", "await ", "try ", "catch ", "throw ", "raise ",
+	}
+	contentLower := strings.ToLower(content)
+	for _, keyword := range codeKeywords {
+		if strings.HasPrefix(contentLower, keyword) {
+			return true
+		}
+	}
+
+	// 3. Contains assignment operators
+	if strings.Contains(content, " = ") || strings.Contains(content, " := ") ||
+		strings.Contains(content, " == ") || strings.Contains(content, " != ") {
+		return true
+	}
+
+	return false
+}
+
 // IsRenameOrMove checks if a file change represents a rename or move operation
 // rather than actual content modification. A rename/move is detected when both
 // the source (fromName) and destination (toName) paths exist and differ.