feat(v2): bootstrap RunAnywhere v2 architecture — C++20 core, 5 frontends, proto3 IDL

.clangd

@@ -0,0 +1,50 @@
+# clangd config — used by IDEs until CMake produces compile_commands.json.
+# After running `cmake --preset macos-debug`, clangd picks up the full flags
+# from build/macos-debug/compile_commands.json.
+
+CompileFlags:
+  Add:
+    - "-std=c++20"
+    - "-xc++"
+    - "-Wall"
+    - "-Wextra"
+    - "-Wpedantic"
+    - "-I${workspaceFolder}/core"
+    - "-I${workspaceFolder}/core/abi"
+  CompilationDatabase: build/macos-debug
+
+Diagnostics:
+  UnusedIncludes: Strict
+  ClangTidy:
+    Add:
+      - modernize-*
+      - performance-*
+      - bugprone-*
+      - cppcoreguidelines-*
+    Remove:
+      - modernize-use-trailing-return-type
+      - modernize-avoid-c-arrays
+      - cppcoreguidelines-avoid-c-arrays
+      - cppcoreguidelines-pro-type-union-access
+      - cppcoreguidelines-pro-bounds-array-to-pointer-decay
+      - cppcoreguidelines-pro-bounds-pointer-arithmetic
+
+Index:
+  Background: Build
+
+InlayHints:
+  Enabled: Yes
+  ParameterNames: Yes
+  DeducedTypes: Yes
+
+---
+# C/ABI headers are plain C — exclude C++ flags.
+If:
+  PathMatch: [ "core/abi/.*\\.h", "core/abi/.*\\.c" ]
+CompileFlags:
+  Add:
+    - "-xc"
+    - "-std=c11"
+  Remove:
+    - "-std=c++20"
+    - "-xc++"

.github/actions/setup-toolchain/action.yml

@@ -1,6 +1,6 @@
 name: Setup Toolchain
 description: |
-  Loads sdk/runanywhere-commons/VERSIONS into $GITHUB_ENV and installs the
+  Loads sdk/legacy/commons/VERSIONS into $GITHUB_ENV and installs the
   per-platform toolchain (Xcode, NDK, JDK, Node, Emscripten, CMake) at the
   versions pinned in VERSIONS. Single source of truth for tool versions.
 
@@ -19,7 +19,7 @@ runs:
       shell: bash
       run: |
         set -euo pipefail
-        VERSIONS_FILE="${GITHUB_WORKSPACE}/sdk/runanywhere-commons/VERSIONS"
+        VERSIONS_FILE="${GITHUB_WORKSPACE}/sdk/legacy/commons/VERSIONS"
         if [ ! -f "$VERSIONS_FILE" ]; then
           echo "::error::VERSIONS file not found at $VERSIONS_FILE"
           exit 1

.github/pull_request_template.md

@@ -44,12 +44,12 @@ Brief description of the changes made.
 Please add the appropriate label(s):
 
 **SDKs:**
-- [ ] `Swift SDK` - Changes to Swift SDK (`sdk/runanywhere-swift`)
-- [ ] `Kotlin SDK` - Changes to Kotlin SDK (`sdk/runanywhere-kotlin`)
-- [ ] `Flutter SDK` - Changes to Flutter SDK (`sdk/runanywhere-flutter`)
-- [ ] `React Native SDK` - Changes to React Native SDK (`sdk/runanywhere-react-native`)
-- [ ] `Web SDK` - Changes to Web SDK (`sdk/runanywhere-web`)
-- [ ] `Commons` - Changes to shared native code (`sdk/runanywhere-commons`)
+- [ ] `Swift SDK` - Changes to Swift SDK (`sdk/legacy/swift`)
+- [ ] `Kotlin SDK` - Changes to Kotlin SDK (`sdk/legacy/kotlin`)
+- [ ] `Flutter SDK` - Changes to Flutter SDK (`sdk/legacy/flutter`)
+- [ ] `React Native SDK` - Changes to React Native SDK (`sdk/legacy/react-native`)
+- [ ] `Web SDK` - Changes to Web SDK (`sdk/legacy/web`)
+- [ ] `Commons` - Changes to shared native code (`sdk/legacy/commons`)
 
 **Sample Apps:**
 - [ ] `iOS Sample` - Changes to iOS example app (`examples/ios`)