chore(release): 0.0.3

Squash-merge lib-standardisation: adopt repo standards across packaging,
tooling, docs, and CI.

- standardize pyproject.toml (canonical packaging, lint config, extras, GSDFC pydoclint)
- add py.typed marker, modernize type hints and Google-style docstrings
- nest generated docs under docs/lib and docs/mcp; add hand-written wiki
- adopt standard Type A PyPI CI pipeline (tag==version guard + quality gate)
- promote generated CHANGELOG.md; bump version to 0.0.3

mail_intake/parsers/headers.py

@@ -10,19 +10,17 @@ The functions here are intentionally simple and tolerant of malformed
 or incomplete header data.
 """
 
-from typing import Dict, List, Tuple, Optional
 
-
-def parse_headers(raw_headers: List[Dict[str, str]]) -> Dict[str, str]:
+def parse_headers(raw_headers: list[dict[str, str]]) -> dict[str, str]:
     """
     Convert a list of Gmail-style headers into a normalized dict.
 
     Args:
-        raw_headers (List[Dict[str, str]]):
+        raw_headers (list[dict[str, str]]):
             List of header dictionaries, each containing `name` and `value` keys.
 
     Returns:
-        Dict[str, str]:
+        dict[str, str]:
             Dictionary mapping lowercase header names to stripped values.
 
     Notes:
@@ -50,7 +48,7 @@ def parse_headers(raw_headers: List[Dict[str, str]]) -> Dict[str, str]:
             }
         ```
     """
-    headers: Dict[str, str] = {}
+    headers: dict[str, str] = {}
 
     for header in raw_headers or []:
         name = header.get("name")
@@ -64,16 +62,16 @@ def parse_headers(raw_headers: List[Dict[str, str]]) -> Dict[str, str]:
     return headers
 
 
-def extract_sender(headers: Dict[str, str]) -> Tuple[str, Optional[str]]:
+def extract_sender(headers: dict[str, str]) -> tuple[str, str | None]:
     """
     Extract sender email and optional display name from headers.
 
     Args:
-        headers (Dict[str, str]):
+        headers (dict[str, str]):
             Normalized header dictionary as returned by `parse_headers()`.
 
     Returns:
-        Tuple[str, Optional[str]]:
+        tuple[str, str | None]:
             A tuple `(email, name)` where `email` is the sender email address
             and `name` is the display name, or `None` if unavailable.