feat(fspy): add no-std Windows module lookup

[wan9chi]

Motivation

The Windows preload initializes under the loader lock, where loading another DLL can deadlock or run unsafe initialization. Extend fspy_nostd to Windows with unit-generic C strings, a WideCStr alias, static wide literals, and get_module_name, which queries an already-loaded module through GetModuleHandleW.

Migrate AttachContext away from LoadLibraryA. KernelBase remains optional, while missing Kernel32 or NTDLL modules are reported to the caller.

[github-actions]

fspy benchmark

linux

dynamic/launch             change  +0.84%  [ -8.68% .. +10.53%]  overhead   +52.07%
dynamic/access             change  -1.01%  [-18.83% ..  +8.65%]  overhead    +6.60%
dynamic/access-relative    change  +0.00%  [-20.26% .. +13.62%]  overhead   +45.27%
static/launch              change  +2.24%  [ -8.95% .. +15.72%]  overhead  +149.79%
static/access              change  +1.48%  [ -9.47% .. +11.22%]  overhead  +890.66%
static/access-relative     change  +0.99%  [ -5.11% ..  +7.97%]  overhead +1227.11%

macos

dynamic/launch             change  +0.15%  [ -2.25% ..  +2.93%]  overhead  +217.19%
dynamic/access             change  +0.36%  [ -2.17% ..  +3.30%]  overhead    +8.09%
dynamic/access-relative    change  +0.22%  [ -3.30% ..  +2.65%]  overhead  +251.75%

windows

dynamic/launch             change  +0.10%  [ -6.10% ..  +5.90%]  overhead   +25.97%
dynamic/access             change  +0.54%  [-11.82% .. +18.59%]  overhead    +1.78%
dynamic/access-relative    change  -0.50%  [-21.72% .. +31.47%]  overhead    +1.73%