fix(test): support Namespace Windows runner

[wan9chi]

What changed

• Switch the Windows test runner from windows-latest to namespace-profile-windows-4c-8g.
• Replace OSC hyperlink milestones with generic, random window-title milestones.
• Queue raw title updates in the terminal and decode milestone titles in the test harness.
• Keep milestone instrumentation disabled in normal builds and support descendant milestone producers.

Motivation

Namespace uses Windows Server 2022 build 20348, whose ConPTY renderer can forward control sequences before earlier screen updates and coalesce intermediate frames. Window-title state is emitted by the renderer after preceding text and cursor state without modifying screen cells. Unix PTYs use the same title token through ordered OSC 2 output, preserving one cross-platform milestone API with latest-observable semantics.

[wan9chi]

• fix(test): support Namespace Windows runner #516 👈 (View in Graphite)
• main

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