Add exact window control tool

[zengfanfan]

Summary

Adds a new exact Window tool for deterministic window workflows without fuzzy matching:

• mode="find" returns matching windows with handle, PID, process, title, status, outer bounds, and client bounds;
• mode="activate" brings an exact handle to foreground and verifies foreground readback;
• mode="bounds" reports or sets exact outer/client bounds and returns actual geometry.

Motivation

The existing App tool is convenience-oriented and supports fuzzy name matching. This PR keeps that behavior unchanged and adds a separate exact path for workflows that must avoid selecting similarly titled windows.

Issue: #316

Public API

Window(mode="find", title="Untitled - Notepad", title_match="contains", process="notepad.exe")
Window(mode="activate", handle=123456, process_id=7890, process="notepad.exe")
Window(mode="bounds", handle=123456, process_id=7890, outer=[x, y, width, height])
Window(mode="bounds", handle=123456, process_id=7890, client=[x, y, width, height])

Matching is exact for handles/PIDs/process basenames and exact-or-contains for titles. Client bounds are converted to outer bounds using current frame/client deltas, then actual geometry is returned after Windows applies constraints.

Testing

Focused checks passed:

uv run pytest tests/test_exact_window_control.py
uv run ruff check src/windows_mcp/desktop/service.py src/windows_mcp/tools/window.py src/windows_mcp/tools/__init__.py tests/test_exact_window_control.py

Focused pytest result:

6 passed

Full repository pytest was also run and still shows the pre-existing baseline failures unrelated to this PR:

uv run pytest
# 324 passed, 3 failed in tests/test_iserror_compliance.py due missing shell/clipboard/registry exported tool functions

Notes

This PR is independent from deterministic drag PR #313 and guarded input PR #315. It does not include local planning documents or private consumer details.