Initial commit: AirCoding V1.0.0 Alpha architecture baseline

Complete architecture document set with multi-model review remediation:
- Frozen interface contracts, runtime semantics, DB schemas
- Event/tool/error/provider registries
- Scheduler and main agent state machines
- C4 module/code views, solution architecture, baseline V1
- Multi-model review reports and joint assessment
- Phase-gate remediation complete (P0/P1/P2/UX resolved)
- Implementation plan with T-000A through T-045
- Reference folders kept as placeholders only

reference/openai-codex/.devcontainer/devcontainer.json

@@ -0,0 +1,27 @@
+{
+  "name": "Codex",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "context": "..",
+    "platform": "linux/arm64"
+  },
+
+  /* Force VS Code to run the container as arm64 in
+     case your host is x86 (or vice-versa). */
+  "runArgs": ["--platform=linux/arm64"],
+
+  "containerEnv": {
+    "RUST_BACKTRACE": "1",
+    "CARGO_TARGET_DIR": "${containerWorkspaceFolder}/codex-rs/target-arm64"
+  },
+
+  "remoteUser": "ubuntu",
+  "customizations": {
+    "vscode": {
+      "settings": {
+        "terminal.integrated.defaultProfile.linux": "bash"
+      },
+      "extensions": ["rust-lang.rust-analyzer", "tamasfe.even-better-toml"]
+    }
+  }
+}