feat(run,check): add --local-cache for script mode and unify cache behavior

- add localCache option to run and check commands
- support --local-cache to use local .vix-scripts directory
- default to global ~/.vix/cache/scripts for clean DX
- update ScriptCMake to switch between local/global cache
- propagate option through RunFlow, RunScript, and CheckScript
- fix build break due to updated get_scripts_root signature
- document --local-cache in CLI help

Author: GaspardKirira

include/vix/cli/commands/check/CheckDetail.hpp

@@ -78,6 +78,9 @@ namespace vix::commands::CheckCommand::detail
     /// Absolute path of the .cpp file to validate.
     fs::path cppFile;
 
+    /// Use local .vix-scripts instead of global ~/.vix/cache/scripts.
+    bool localCache = false;
+
     /// Enable AddressSanitizer + UBSan.
     bool enableSanitizers = false;
 

include/vix/cli/commands/run/RunDetail.hpp

@@ -130,6 +130,8 @@ namespace vix::commands::RunCommand::detail
 
     bool warnedVixFlagAfterDoubleDash = false;
     std::string warnedArg;
+
+    bool localCache = false;
   };
 
   /**
@@ -353,7 +355,7 @@ namespace vix::commands::RunCommand::detail
   /**
    * @brief Return the root directory used for generated script projects.
    */
-  fs::path get_scripts_root();
+  fs::path get_scripts_root(bool localCache);
 
   /**
    * @brief Detect whether a .cpp script uses the Vix runtime.

src/commands/RunCommand.cpp

@@ -1296,6 +1296,7 @@ namespace vix::commands::RunCommand
     out << "  --ubsan                       Enable UBSan only\n";
     out << "  --with-sqlite                 Enable SQLite support for script mode\n";
     out << "  --with-mysql                  Enable MySQL support for script mode\n\n";
+    out << "  --local-cache                 Use local .vix-scripts instead of global cache\n";
 
     out << "Documentation:\n";
     out << "  --docs                        Enable auto docs (sets VIX_DOCS=1)\n";

src/commands/check/CheckScript.cpp

@@ -182,7 +182,7 @@ namespace vix::commands::CheckCommand::detail
     const bool enableUbsanOnly = opt.enableUbsanOnly;
     const std::string exeName = script.stem().string();
 
-    fs::path scriptsRoot = run::get_scripts_root();
+    fs::path scriptsRoot = run::get_scripts_root(opt.localCache);
     std::error_code ec;
     fs::create_directories(scriptsRoot, ec);
     if (ec)

src/commands/run/RunFlow.cpp

@@ -439,6 +439,10 @@ namespace vix::commands::RunCommand::detail
       {
         opt.verbose = true;
       }
+      else if (a == "--local-cache")
+      {
+        opt.localCache = true;
+      }
       else if (a == "--log-level" || a == "--loglevel")
       {
         opt.logLevel = take_value(args, i, a, opt);

src/commands/run/RunScript.cpp

@@ -456,7 +456,7 @@ namespace vix::commands::RunCommand::detail
       ScriptProjectState state;
       state.script = fs::absolute(opt.cppFile).lexically_normal();
       state.exeName = state.script.stem().string();
-      state.scriptsRoot = get_scripts_root();
+      state.scriptsRoot = get_scripts_root(opt.localCache);
 
       const std::string scriptCacheKey = hex_u64(
           fnv1a_64("script-cache:" + state.script.string()));

src/commands/run/detail/ScriptCMake.cpp

@@ -1290,8 +1290,11 @@ namespace vix::commands::RunCommand::detail
     return false;
   }
 
-  fs::path get_scripts_root()
+  fs::path get_scripts_root(bool localCache)
   {
+    if (localCache)
+      return fs::current_path() / ".vix-scripts";
+
     if (const auto home = home_dir(); home)
       return fs::path(*home) / ".vix" / "cache" / "scripts";