fix(build): make build/clean tools non-blocking to match async contract

[fivestar1103]

Problem

build_solution, build_project, and clean_solution are documented as asynchronous ("runs asynchronously; use build_status to check progress; returns immediately after starting the build"), but they block until the build/clean fully completes.

This shows up in daily real-world use: I drive builds through this MCP on a large Unreal Engine 5 (C++) solution, and build_solution consistently returns The operation timed out. instead of Build started. Because the blocking call also freezes the Visual Studio UI thread for the whole build, build_status and build_cancel can't run either — so the documented "start build, then poll build_status" workflow is impossible on any large solution.

Root cause

src/CodingWithCalvin.MCPServer/Services/VisualStudioService.cs calls the EnvDTE SolutionBuild APIs with the wait flag set to true, right after SwitchToMainThreadAsync():

dte.Solution.SolutionBuild.Build(true);                       // BuildSolutionAsync
dte.Solution.SolutionBuild.BuildProject(config, path, true);  // BuildProjectAsync
dte.Solution.SolutionBuild.Clean(true);                       // CleanSolutionAsync

The final boolean is WaitForBuildToFinish / WaitForCleanToFinish; true blocks on the UI thread until the whole operation finishes.

Fix

Pass false so the build/clean is queued and the call returns immediately. This restores the documented async behavior and lets build_status observe the InProgress -> Done transition as intended.

Testing

No automated coverage — the repo has no test harness yet (#11); this is a minimal per-call flag flip.