feat: add parser functions with tests

tests/test_parsers.py

@@ -0,0 +1,24 @@
+import sys, os
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+from scraper import extract_hashtags, extract_mentions, profile_slug_from_url
+
+def test_extract_hashtags_basic():
+    assert extract_hashtags("Hello #world #foo") == ["#world", "#foo"]
+
+def test_extract_hashtags_empty():
+    assert extract_hashtags("No tags here") == []
+
+def test_extract_hashtags_deduplicates():
+    assert extract_hashtags("#foo #foo #bar") == ["#foo", "#bar"]
+
+def test_extract_mentions_basic():
+    assert extract_mentions("Hey @alice and @bob") == ["@alice", "@bob"]
+
+def test_extract_mentions_empty():
+    assert extract_mentions("No mentions") == []
+
+def test_profile_slug_from_url():
+    assert profile_slug_from_url("https://www.instagram.com/licmuunisul/") == "licmuunisul"
+
+def test_profile_slug_trailing_slash():
+    assert profile_slug_from_url("https://www.instagram.com/licmuunisul") == "licmuunisul"