refactor: modernize typing and defaults across core API (#1299)

* refactor: modernize typing to PEP 604 style across core API

- Replace Union[X, Y] with X | Y
- Replace Optional[X] with X | None
- Replace List[X], Dict[K, V], Tuple[X] with lowercase builtins
- Import Callable from collections.abc instead of typing
- Fix mutable default arguments (Config(), DependencyMap(), list defaults)
- Improve OpenAPI union schema generation using get_origin/get_args
- Make TemplateInterface.__init__ accept *args/**kwargs
- Clean up unused typing imports

Co-authored-by: Sachin-Bhat <sachin.bhat@users.noreply.github.com>
Made-with: Cursor

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix: lint and Generator typing failures

- robyn/responses.py: Generator[str | None | None] is malformed (typing.Generator
  needs 3 args yield/send/return); restore Generator[str, None, None] | AsyncGenerator[str, None].
- robyn/processpool.py: process_pool: List = [] → list = [] (List was unimported).
- integration_tests/base_routes.py: TestTypedBody.items: List[str] → list[str].
- Drop unused typing imports flagged by ruff F401: Optional in robyn/ai.py,
  Dict/List in robyn/mcp.py, Protocol/TypeAlias in robyn/openapi.py, the
  TYPE_CHECKING-gated SubRouter import in robyn/router.py.
- ruff-format pass: insert PEP 8 blank lines between top-level defs across
  ai/authentication/cli/logger/mcp/processpool/reloader/responses/router/
  types/__init__.py.

Fixes ubuntu/macos/windows tests, codspeed-benchmarks, lint, and pre-commit.ci.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix: restore mutable defaults for Config/DependencyMap and handle PEP 604 unions in param coercion

Two test regressions exposed by the typing modernization:

1. test_subrouter_global_dependency_injection expected app's later
   inject_global(GLOBAL_DEPENDENCY="GLOBAL DEPENDENCY") to override the
   subrouter's earlier inject_global(...="GLOBAL DEPENDENCY OVERRIDE").
   That worked on main only because BaseRobyn(... config=Config(),
   dependencies=DependencyMap()) used mutable defaults — every Robyn /
   SubRouter constructed without explicit args shared the same instances,
   so app.inject_global mutated the same dict the subrouter held. The PR
   moved both to None + lazy-init in __init__, breaking the sharing.
   Restored the mutable defaults to match main's semantics. SubRouter
   signature also restored to match main (Config()/OpenAPI() defaults).

2. test_easy_access_optional_present[sync|async] returned 500 because
   robyn/_param_utils.py:unwrap_optional only recognized typing.Union
   via .__origin__. PEP 604 `int | None` is types.UnionType and has no
   __origin__ attribute, so unwrap_optional returned the raw union and
   coerce_value tried (int | None)("30"), raising. Replaced
   getattr(annotation, "__origin__", None) with typing.get_origin and
   accept both Union and types.UnionType. Same fix applied to
   is_list_type for symmetry.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Sanskar Jethi <sansyrox@gmail.com>
Co-authored-by: Sachin-Bhat <sachin.bhat@users.noreply.github.com>
Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 5 people

integration_tests/base_routes.py

@@ -5,7 +5,7 @@
 import pathlib
 import time
 from collections import defaultdict
-from typing import List, Optional, TypedDict
+from typing import TypedDict
 
 from integration_tests.subroutes import di_subrouter, static_router, sub_router
 from robyn import Headers, Request, Response, Robyn, SSEMessage, SSEResponse, WebSocketDisconnect, jsonify, serve_file, serve_html
@@ -1263,7 +1263,7 @@ def sample_openapi_endpoint():
 
 class Initial(Body):
  is_present: bool
- letter: Optional[str]
+ letter: str | None
 
 
 class FullName(Body):
@@ -1273,7 +1273,7 @@ class FullName(Body):
 
 
 class TestTypedBody(Body):
- items: List[str]
+ items: list[str]
  numbers: list[int]
 
 
@@ -1501,22 +1501,22 @@ async def easy_access_async(id: int, q: str, page: int = 1):
 
 
 @app.get("/easy/sync/optional")
-def easy_access_optional_sync(name: str, age: Optional[int] = None):
+def easy_access_optional_sync(name: str, age: int | None = None):
  return {"name": name, "age": age}
 
 
 @app.get("/easy/async/optional")
-async def easy_access_optional_async(name: str, age: Optional[int] = None):
+async def easy_access_optional_async(name: str, age: int | None = None):
  return {"name": name, "age": age}
 
 
 @app.get("/easy/sync/list")
-def easy_access_list_sync(tag: List[str]):
+def easy_access_list_sync(tag: list[str]):
  return {"tags": tag}
 
 
 @app.get("/easy/async/list")
-async def easy_access_list_async(tag: List[str]):
+async def easy_access_list_async(tag: list[str]):
  return {"tags": tag}
 
 
@@ -1715,7 +1715,7 @@ def main():
  app.include_router(static_router)
 
  class BasicAuthHandler(AuthenticationHandler):
- def authenticate(self, request: Request) -> Optional[Identity]:
+ def authenticate(self, request: Request) -> Identity | None:
  token = self.token_getter.get_token(request)
  if token is not None:
  # Useless but we call the set_token method for testing purposes