Task: Implement Hotfix: Windows CI builds timing out / failing on header dependency scanning

Disable CMake's automatic C++20 module dependency scanning (CMAKE_CXX_SCAN_FOR_MODULES) so Ninja stops invoking clang-scan-deps for every translation unit on the Windows legs.

• CMAKE_CXX_SCAN_FOR_MODULES is off for the project.
• Local build succeeds; no behaviour change on Linux/macOS.

Root cause (from Windows CI logs, runs 29669098639 and 29548329266):

• Since CMake 3.28, the Ninja generator auto-enables CMAKE_CXX_SCAN_FOR_MODULES for compilers that support P1689 dependency scanning (MSVC, Clang) — even for projects that use no C++20 modules at all. This adds a clang-scan-deps pre-pass per translation unit, invoked through cmd.exe /C "...".
• cmd.exe has an ~8191-character command-line limit. ORE Studio's compile commands (many Boost -D defines plus a long transitive -I list) exceed that on some targets, so the scan command is silently truncated and drops trailing -I flags — observed: ores.diff/include missing from the scan invocation for ores.dq.core, producing "file not found: ores.diff/domain/field_value.hpp".
• The same scanning pre-pass, run for every TU across the whole project on the slower Windows runners, is the most likely explanation for the msvc-release leg hanging past the 6h timeout.
• The project does not use C++20 modules, so the scan pass buys nothing. Fix: set CMAKE_CXX_SCAN_FOR_MODULES OFF globally in the root CMakeLists.txt, before subdirectories are added.

Verified locally on linux-clang-debug-make: configure is clean and ores.dq.core.lib (the target that failed on Windows) builds successfully with the setting off, no behaviour change. Windows-side verification will happen via CI on the PR, since no Windows runner is available locally.

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Set CMAKE_CXX_SCAN_FOR_MODULES OFF globally in the root CMakeLists.txt, disabling CMake's automatic C++20 module dependency-scanning pass (clang-scan-deps=/P1689) for Ninja + MSVC/Clang. The project uses no C++20 modules, so the pass was pure overhead; on Windows it was invoked through =cmd.exe, whose ~8191-char command-line limit silently truncated long transitive -I=/-D= argument lists, dropping the ores.diff include path for ores.dq.core and causing "file not found" errors, and adding per-TU scan overhead that is the most likely cause of the msvc-release leg hanging past the 6h CI timeout.

Acceptance met: setting confirmed off, local configure/build on linux-clang-debug-make clean with no behaviour change (full compass build completed green in the background). Landed via PR #1645, merge-commit to main; Windows CI on the next scheduled run is the platform-specific confirmation, since no Windows runner was available locally.