Python: Fix Python pyright package scoping and typing remediation (#4426)

* Fix Python pyright package scoping and typing remediation

Implements issue #4407 by removing the root pyright include, adding package-level pyright includes, and resolving pyright/mypy typing issues across Python packages. Also cleans unnecessary casts and applies line-level, rule-specific ignores where external libraries are too dynamic.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Reduce pyright cost in handoff cloning

Simplify cloned_options construction in HandoffAgentExecutor to avoid expensive TypedDict narrowing/inference in _handoff.py, which was causing pyright to spend a long time in orchestrations.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix types

* Fix lint and type-check regressions

Resolve current Python package check failures across lint, pyright, and mypy after recent code changes, including purview/declarative pyright issues and multiple ruff simplification findings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fixed hooks

* Stabilize package tests and test tasks

Resolve cross-package non-integration test failures, simplify streaming type flow, harden locale/culture handling, and standardize package test poe tasks to exclude integration tests where applicable.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* lots of small fixes

* Fix current Python test regressions

Address current failing unit tests in azure-ai, bedrock, and azure-cosmos while keeping Bedrock parsing logic inline (no new static helper methods).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* small fixes

* small fixes

* removed pydantic from json

* final updates

* fix core

* fix tests

* fix obser

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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

python/CODING_STANDARD.md

@@ -27,6 +27,12 @@ Public modules must include a module-level docstring, including `__init__.py` fi
 
 ## Type Annotations
 
+We use typing as a helper, it is not a goal in and of itself, so be pragmatic about where and when to strictly type, versus when to use a targetted cast or ignore.
+In general, the public interfaces of our classes, are important to get right, internally it is okay to have loosely typed code, as long as tests cover the code itself.
+This includes making a conscious choice when to program defensively, you can always do `getattr(item, 'attribute')` but that might end up causing you issues down the road
+because the type of `item` in this case, should have that attribute and if it doesn't it points to a larger issue, so if the type is expected to have that attribute, you should
+use `item.attribute` to ensure it fails at that point, rather then somewhere downstream where a value is expected but none was found.
+
 ### Future Annotations
 
 > **Note:** This convention is being adopted. See [#3578](https://github.com/microsoft/agent-framework/issues/3578) for progress.
@@ -79,6 +85,21 @@ def process_config(config: MutableMapping[str, Any]) -> None:
     ...
 ```
 
+### Typing Ignore and Cast Policy
+
+Use typing as a helper first and suppressions as a last resort:
+
+- **Prefer explicit typing before suppression**: Start with clearer type annotations, helper types, overloads,
+  protocols, or refactoring dynamic code into typed helpers. Prioritize performance over completeness of typing, but make a good-faith effort to reduce uncertainty with typing before ignoring. Prefer to use a cast over a typeguard function since that does add overhead.
+- **Avoid redundant casts**: Do not add `cast(...)` if the type already matches; casts should be reserved for
+  unavoidable narrowing where the runtime contract is known, we will use mypy's check on redundant casts to enforce this.
+- **Avoid multiple assignments**: Avoid assigning multiple variables just to get typing to pass, that has performance impact while typing should not have that.
+- **Line-level pyright ignores only**: If suppression is still required, use a line-level rule-specific ignore
+  (`# pyright: ignore[reportGeneralTypeIssues]`), file-level is allowed if there is a compelling reason for it, that should be documented right beneath the ignore.
+  Never change the global suppression flags for mypy and pyright unless the dev team okays it.
+- **Private usage boundary**: Accessing private members across `agent_framework*` packages can be acceptable for this
+  codebase, but private member usage for non-Agent Framework dependencies should remain flagged.
+
 ## Function Parameter Guidelines
 
 To make the code easier to use and maintain: