V2: WASI, -r flag, CI pipeline, examples & tests cleanup

WASI / wasm32 target support
- Auto-detect /usr/share/wasi-sysroot on Linux when target starts_with("wasm32")
- Skip -march/-mtune for wasm (clang rejects them)
- Apply -fno-exceptions -fno-c++-static-destructors -mllvm -wasm-enable-sjlj
  -D_WASI_EMULATED_SIGNAL to wasm builds (compile + std PCM, kept in sync)
- .wasm output extension in expectedOutputFor and link command
- EnableWasiBrowserRuntime(cfg): opt-in helper that drops index.html +
  runtime.js next to the .wasm; runtime.js reads window.CRAFTER_WASM_URL
  set in the templated index.html so a single shim handles any output name

-r run flag in the CLI: build then exec the artifact (host targets only;
  rejects libraries; auto .exe/.wasm extension handling)

CI pipeline (.forgejo/workflows/ci.yaml)
- Triggers: PR/push to master + manual dispatch
- Single arch-latest container job: install deps, bootstrap, self-rebuild,
  run tests, cross-compile mingw, package both archives, upload artifacts
- Rolling 'latest' release published only on push/dispatch to master

mingw cross-compile from Linux now works end-to-end:
- ExternalDependency cache key includes target so per-target glslang builds
  don't collide; CMAKE_BUILD_TYPE=Release pinned (otherwise glslang appends
  'd' to lib names and breaks linking); cross-compile cmake flags
  (CMAKE_SYSTEM_NAME=Windows, CMAKE_*_COMPILER_TARGET=...)
- project.cpp accepts --target=<triple>; Linux-only -Wl,--export-dynamic
  and -ldl are gated; mingw glslang skips the standalone exe (its libgcc_eh
  link pulls pthread which mingw doesn't link by default)
- mingw compile uses -femulated-tls so std::__once_callable etc reference
  the same emutls symbols libstdc++ provides
- mingw link auto-adds -lstdc++exp -lpthread

GetCrafterBuildHome() exposed from the Platform module; LoadProject (Linux
+ Windows) now both use it instead of duplicating the resolution.

Examples reorg: hello-world, library, with-module, wasi, tests — each with
its own README. Tests reorg: per-test directory with inner/ fixture, no
shared tests/fixtures/ tree. New Wasi test verifies .wasm magic bytes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

interfaces/Crafter.Build-Clang.cppm

@@ -48,6 +48,12 @@ export namespace Crafter {
     struct Test;
 
     struct TestRunner {
+        // Quoting style for {args} when this runner is used. Args reach
+        // whichever shell the runner ultimately delivers them to: Host for
+        // Local + Cmd-prefix (host shell parses), Sh for Ssh (remote bash),
+        // Cmd for SshWin (remote cmd.exe).
+        enum class Shell { Host, Sh, Cmd };
+
         std::string copy;
         std::string exec;
         std::string cleanup;
@@ -57,13 +63,16 @@ export namespace Crafter {
         // is available; non-zero = skip every Test using this runner with a
         // "runner unavailable" message. Empty = always available (e.g., Local).
         std::string probe;
+        Shell argsShell = Shell::Host;
 
         bool IsLocal() const { return exec.empty(); }
 
         static CRAFTER_API TestRunner Local();
         static CRAFTER_API TestRunner Ssh(std::string host, std::string remoteDir = "/tmp/crafter-tests");
         static CRAFTER_API TestRunner SshWin(std::string host, std::string remoteDir = "C:/temp/crafter-tests");
-        static CRAFTER_API TestRunner QemuUser(std::string qemuBin);
+        static CRAFTER_API TestRunner Wsl(std::string remoteDir = "/tmp/crafter-tests-wsl");
+        static CRAFTER_API TestRunner Cmd(std::string command);
+        static CRAFTER_API std::optional<TestRunner> FromSpec(std::string_view spec);
         static CRAFTER_API TestRunner FromEnv(std::string_view target, TestRunner fallback = Local());
     };
 
@@ -118,4 +127,12 @@ export namespace Crafter {
     CRAFTER_API BuildResult Build(Configuration& config, std::unordered_map<fs::path, std::shared_future<BuildResult>>& depResults, std::mutex& depMutex);
 
     CRAFTER_API int Run(int argc, char** argv);
+
+    // Add a small index.html + runtime.js pair next to the .wasm output so the
+    // build can be loaded directly in a browser (just `serve` the bin dir and
+    // open it). Opt-in: WASI builds destined for wasmtime/wasmer don't need
+    // this and shouldn't carry the extra files. Call from project.cpp after
+    // outputName is set; index.html is generated against the current
+    // outputName so renaming the binary later requires another call.
+    CRAFTER_API void EnableWasiBrowserRuntime(Configuration& cfg);
 }

interfaces/Crafter.Build-External.cppm

@@ -53,5 +53,6 @@ export namespace Crafter {
 
     CRAFTER_API ExternalBuildResult BuildExternal(
         const ExternalDependency& dep,
+        std::string_view target,
         std::atomic<bool>& cancelled);
 }

interfaces/Crafter.Build-Platform.cppm

@@ -39,4 +39,8 @@ namespace Crafter {
     export CRAFTER_API CommandResult RunCommandWithTimeout(std::string_view command, std::chrono::seconds timeout);
     std::string GetBaseCommand(const Configuration& config);
     export CRAFTER_API Configuration LoadProject(const fs::path& projectFile, std::span<const std::string_view> args);
+    // Resolves the directory holding distributed runtime assets (Crafter.Build
+    // module sources, wasi-runtime/, etc). Honors CRAFTER_BUILD_HOME; otherwise
+    // derives <prefix>/share/crafter-build from the running executable's path.
+    export CRAFTER_API fs::path GetCrafterBuildHome();
 }

interfaces/Crafter.Build-Test.cppm

@@ -29,6 +29,19 @@ export namespace Crafter {
         int jobs = 0;
         std::optional<std::chrono::seconds> timeoutOverride;
         bool listOnly = false;
+        // Only tests whose Configuration::target equals targetFilter are run.
+        // Set from --target=... (host triple if unspecified). Tests for other
+        // targets are silently excluded so e.g. `--target=mingw` doesn't drag
+        // in host-only outer-driver tests.
+#ifdef _WIN32
+        std::string targetFilter = "x86_64-pc-windows-msvc";
+#else
+        std::string targetFilter = "x86_64-pc-linux-gnu";
+#endif
+        // CLI override for --runner=<spec>: applies to every test in the run.
+        // Target scoping is unnecessary because targetFilter ensures the run
+        // contains only one target's tests.
+        std::optional<std::string> runnerOverride;
     };
 
     struct TestSummary {
@@ -41,6 +54,15 @@ export namespace Crafter {
         bool AllPassed() const { return failed == 0 && crashed == 0 && timedOut == 0; }
     };
 
-    CRAFTER_API TestSummary RunTests(Configuration& projectCfg, const RunTestsOptions& opts);
+    CRAFTER_API TestSummary RunTests(Configuration& projectCfg, const RunTestsOptions& opts, std::span<const std::string_view> projectArgs = {});
     CRAFTER_API TestResult RunSingleTest(const Test& test, const std::filesystem::path& binary, std::chrono::seconds timeout);
+
+    // Parent-project access for test fixtures. Run() sets the pointer to the
+    // root project's Configuration before discovery; fixtures call ParentLib()
+    // to obtain a Configuration* for one of the parent's libraries (or the
+    // parent itself) so they can declare it as a dependency without rebuilding
+    // the lib config from scratch. Lookup is by Configuration::name and
+    // recurses through the parent's dependency graph.
+    CRAFTER_API void SetParentProject(Configuration* parent);
+    CRAFTER_API Configuration* ParentLib(std::string_view name);
 }