Merge PR #275: Add Dart, Scala, SCSS, SASS, Elixir, Lua, Perl language detection

Thank you @PaawanBarach for this excellent contribution! 🎉

Adds pattern-based language detection for 7 new programming languages with comprehensive test coverage.

✅ 70 regex patterns with smart weight distribution
✅ Framework-specific patterns (Flutter, case classes, mixins)
✅ 7 new tests, all passing (30/30 total)
✅ No regressions, backward compatible

This resolves #165 and significantly expands our language support!

src/skill_seekers/cli/language_detector.py

@@ -310,6 +310,67 @@ LANGUAGE_PATTERNS: dict[str, list[tuple[str, int]]] = {
         (r"\b_ready\s*\(", 4),
         (r"\b_process\s*\(", 4),
     ],
+    "dart": [
+        (r"\bimport\s+['\"]package:", 5),
+        (r"\bclass\s+\w+\s+extends\s+StatelessWidget", 5),
+        (r"\bclass\s+\w+\s+extends\s+StatefulWidget", 5),
+        (r"@override\b", 4),
+        (r"\bWidget\s+build\s*\(", 5),
+        (r"\bimport\s+['\"]dart:", 5),
+        (r"\bfinal\s+\w+\s+\w+;", 4),
+        (r"=>\s*\w+\(", 4),
+        (r"\basync\s*\{", 3),
+        (r"\bawait\s+", 3),
+        (r"\bsetState\s*\(", 4),
+        (r"\bvoid\s+main\s*\(", 3),
+    ],
+    "scala": [
+        (r"\bcase\s+class\s+\w+", 5),
+        (r"\btrait\s+\w+", 5),
+        (r"\bdef\s+\w+[^:]*:\s*\w+\s*=", 5),
+        (r"\bimport\s+scala\.", 4),
+        (r"\bmatch\s*\{", 4),
+        (r"\bval\s+\w+\s*:\s*\w+\s*=", 4),
+        (r"\bobject\s+\w+", 5),
+        (r"=>", 3),
+        (r"\bdef\s+\w+\[\w+\]", 4),
+        (r"\bextends\s+\w+", 2),
+    ],
+    "elixir": [
+        (r"\bdefmodule\s+[A-Z]", 5),
+        (r"\bdef\s+\w+\s+do\b", 5),
+        (r"\bdefp\s+\w+", 5),
+        (r"\|>", 5),
+        (r"\buse\s+[A-Z]", 4),
+        (r"\balias\s+[A-Z]", 4),
+        (r"#\{", 4),
+        (r"@[\w_]+", 3),
+        (r"\bcase\s+\w+\s+do\b", 3),
+    ],
+    "lua": [
+        (r"\blocal\s+\w+\s*=", 5),
+        (r"\.\.\.(?!\.)", 5),
+        (r"\brepeat\b.*\buntil\b", 5),
+        (r"~=", 4),
+        (r"\belseif\b", 4),
+        (r"\bthen\b", 3),
+        (r"\bfunction\s+\w+\s*\(", 3),
+        (r"\bend\b", 2),
+    ],
+    "perl": [
+        (r"\bmy\s+\$\w+", 5),
+        (r"\buse\s+strict", 5),
+        (r"\buse\s+warnings", 5),
+        (r"\bsub\s+\w+\s*\{", 5),
+        (r"\bchomp\s*\(", 5),
+        (r"@\w+\s*=", 5),
+        (r"%\w+\s*=", 5),
+        (r"\$\w+\s*=~\s*/", 4),
+        (r"\$[0-9]+", 4),
+        (r"->", 3),
+    ],
+
+
     # ===== Markup/Config Languages =====
     "html": [
         (r"<!DOCTYPE\s+html>", 5),
@@ -327,6 +388,28 @@ LANGUAGE_PATTERNS: dict[str, list[tuple[str, int]]] = {
         (r"#[\w-]+\s*\{", 2),
         (r"@import", 2),
     ],
+    "scss": [
+        (r"\$[\w-]+\s*:", 5),
+        (r"@mixin\s+[\w-]+", 5),
+        (r"@include\s+[\w-]+", 5),
+        (r"@extend\s+", 4),
+        (r"@function\s+[\w-]+", 4),
+        (r"&[:\.]", 4),
+        (r"#\{", 4),
+        (r"@import\s+['\"]", 3),
+        (r"@if\s+", 5),
+        (r"@for\s+", 5),
+        (r"@each\s+", 5),
+    ],
+    "sass": [
+        (r"\$[\w-]+\s*:", 5),
+        (r"=[\w-]+", 5),
+        (r"\+[\w-]+", 5),
+        (r"@for\s+.+\s+through\s+", 5),
+        (r"@mixin\s+[\w-]+", 4),
+        (r"@if\s+", 4),
+        (r"^\s{2,}[\w-]+:", 3),
+    ],
     "json": [
         (r"^\s*\{", 3),
         (r"^\s*\[", 3),