feat(aircoding): AirCoding V2 baseline — deterministic multi-agent architecture

Forked from OpenCode v1.17.4 with multi-agent system:
- 5 agents: aircoding, scheduler, worker, architect, reviewer
- Deterministic DAG scheduling engine (coordinator_tick)
- Tool whitelists as hard enforcement
- AirCoding validation plugin
- System prompt injection for routing
- V1 requirements: C4 docs, ADR, AGENTS.md, debug-log.md
- Design documents in docs/

nix/node_modules.nix

@@ -0,0 +1,85 @@
+{
+  lib,
+  stdenvNoCC,
+  bun,
+  rev ? "dirty",
+  hash ?
+    (lib.pipe ./hashes.json [
+      builtins.readFile
+      builtins.fromJSON
+    ]).nodeModules.${stdenvNoCC.hostPlatform.system},
+}:
+let
+  packageJson = lib.pipe ../packages/opencode/package.json [
+    builtins.readFile
+    builtins.fromJSON
+  ];
+  platform = stdenvNoCC.hostPlatform;
+  bunCpu = if platform.isAarch64 then "arm64" else "x64";
+  bunOs = if platform.isLinux then "linux" else "darwin";
+in
+stdenvNoCC.mkDerivation {
+  pname = "opencode-node_modules";
+  version = "${packageJson.version}+${lib.replaceString "-" "." rev}";
+
+  src = lib.fileset.toSource {
+    root = ../.;
+    fileset = lib.fileset.intersection (lib.fileset.fromSource (lib.sources.cleanSource ../.)) (
+      lib.fileset.unions [
+        ../packages
+        ../bun.lock
+        ../package.json
+        ../patches
+        ../install # required by desktop build (cli.rs include_str!)
+        ../.github/TEAM_MEMBERS # required by @opencode-ai/script
+      ]
+    );
+  };
+
+  impureEnvVars = lib.fetchers.proxyImpureEnvVars ++ [
+    "GIT_PROXY_COMMAND"
+    "SOCKS_SERVER"
+  ];
+
+  nativeBuildInputs = [ bun ];
+
+  dontConfigure = true;
+
+  buildPhase = ''
+    runHook preBuild
+    export BUN_INSTALL_CACHE_DIR=$(mktemp -d)
+    bun install \
+      --cpu="${bunCpu}" \
+      --os="${bunOs}" \
+      --filter '!./' \
+      --filter './packages/opencode' \
+      --filter './packages/desktop' \
+      --filter './packages/app' \
+      --frozen-lockfile \
+      --ignore-scripts \
+      --no-progress
+    bun --bun ${./scripts/canonicalize-node-modules.ts}
+    bun --bun ${./scripts/normalize-bun-binaries.ts}
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+    mkdir -p $out
+    find . -type d -name node_modules -exec cp -R --parents {} $out \;
+    runHook postInstall
+  '';
+
+  dontFixup = true;
+
+  outputHashAlgo = "sha256";
+  outputHashMode = "recursive";
+  outputHash = hash;
+
+  meta.platforms = [
+    "aarch64-linux"
+    "x86_64-linux"
+    "aarch64-darwin"
+    "x86_64-darwin"
+  ];
+}