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/ingestion/reader.py

@@ -16,16 +16,17 @@ It coordinates:
 No provider-specific logic or API semantics are permitted in this layer.
 """
 
+from collections.abc import Iterator
 from datetime import datetime
-from typing import Iterator, Dict, Any
+from typing import Any
 
 from mail_intake.adapters.base import MailIntakeAdapter
+from mail_intake.exceptions import MailIntakeParsingError
 from mail_intake.models.message import MailIntakeMessage
 from mail_intake.models.thread import MailIntakeThread
-from mail_intake.parsers.headers import parse_headers, extract_sender
 from mail_intake.parsers.body import extract_body
+from mail_intake.parsers.headers import extract_sender, parse_headers
 from mail_intake.parsers.subject import normalize_subject
-from mail_intake.exceptions import MailIntakeParsingError
 
 
 class MailIntakeReader:
@@ -87,9 +88,9 @@ class MailIntakeReader:
             query (str):
                 Provider-specific query string used to filter messages.
 
-        Yields:
-            MailIntakeThread:
-                An iterator of `MailIntakeThread` instances.
+        Returns:
+            Iterator[MailIntakeThread]:
+                An iterator over `MailIntakeThread` instances.
 
         Raises:
             `MailIntakeParsingError`:
@@ -101,7 +102,7 @@ class MailIntakeReader:
                 - Messages are grouped by `thread_id` and yielded as complete
                   thread objects containing all associated messages.
         """
-        threads: Dict[str, MailIntakeThread] = {}
+        threads: dict[str, MailIntakeThread] = {}
 
         for ref in self._adapter.iter_message_refs(query):
             raw = self._adapter.fetch_message(ref["message_id"])
@@ -119,12 +120,12 @@ class MailIntakeReader:
 
         return iter(threads.values())
 
-    def _parse_message(self, raw_message: Dict[str, Any]) -> MailIntakeMessage:
+    def _parse_message(self, raw_message: dict[str, Any]) -> MailIntakeMessage:
         """
         Parse a raw provider message into a `MailIntakeMessage`.
 
         Args:
-            raw_message (Dict[str, Any]):
+            raw_message (dict[str, Any]):
                 Provider-native message payload.
 
         Returns: