refactor: improve tag extraction and type annotations

- Ensures tag extraction is case-insensitive
- Adds type annotations for better code clarity and maintainability

src/llm_cli/utils/_extract_between_tags.py

@@ -1,11 +1,14 @@
 def extract_between_tags(content: str | None, tag: str = "Answer") -> str:
     if content is None:
         return ""
-    start: int = content.find("<" + tag + ">")
+    content_lower: str = content.lower()
+    opening_tag: str = f"<{tag}>".lower()
+    start: int = content_lower.find(opening_tag)
     if start >= 0:
-        start += len(tag) + 2
+        start += len(opening_tag)
         content = content[start:]
-    end: int = content.find("</" + tag + ">")
+    closing_tag: str = f"</{tag}>".lower()
+    end: int = content_lower.find(closing_tag)
     if end >= 0:
         content = content[:end]
     return content.strip()

src/llm_cli/utils/_get_prompt.py

@@ -1,7 +1,8 @@
 import importlib.resources
+from importlib.resources.abc import Traversable
 
 
 def get_prompt(name: str) -> str:
-    prompts_dir = importlib.resources.files("llm_cli.assets.prompts")
-    fpath = prompts_dir / f"{name}.md"
+    prompts_dir: Traversable = importlib.resources.files("llm_cli.assets.prompts")
+    fpath: Traversable = prompts_dir / f"{name}.md"
     return fpath.read_text()