Fix stale labels, grammar, and comments from sandbox rename

- Fix display label `image:` → `name:` for SnapshotPulling/SnapshotPulled
  in format_event_detail
- Fix grammar: "an Sandbox" → "a Sandbox" in README and parallel.rs
- Fix typo: "sandboxs" → "sandboxes" in parallel.rs
- Update remaining "execution environment" comments to "sandbox"

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/arc-web/app/api-client.test.ts

@@ -0,0 +1,60 @@
+import { describe, test, expect, beforeEach, mock } from "bun:test";
+import { apiJson } from "./api-client";
+
+const originalFetch = globalThis.fetch;
+
+beforeEach(() => {
+  globalThis.fetch = originalFetch;
+});
+
+describe("apiJson", () => {
+  test("returns parsed JSON on 200", async () => {
+    globalThis.fetch = mock(() =>
+      Promise.resolve(new Response(JSON.stringify({ id: 1, name: "test" }), {
+        status: 200,
+        headers: { "Content-Type": "application/json" },
+      }))
+    );
+
+    const result = await apiJson<{ id: number; name: string }>("/items/1");
+
+    expect(result).toEqual({ id: 1, name: "test" });
+  });
+
+  test("throws Response with status 404 and null body on not found", async () => {
+    globalThis.fetch = mock(() =>
+      Promise.resolve(new Response("Not Found: /items/999", { status: 404 }))
+    );
+
+    try {
+      await apiJson("/items/999");
+      expect.unreachable("should have thrown");
+    } catch (thrown) {
+      expect(thrown).toBeInstanceOf(Response);
+      const res = thrown as Response;
+      expect(res.status).toBe(404);
+      expect(res.body).toBeNull();
+    }
+  });
+
+  test("throws Response with status 500 and null body, stripping sensitive details", async () => {
+    globalThis.fetch = mock(() =>
+      Promise.resolve(
+        new Response(
+          "Internal error: database connection string is postgres://admin:secret@db.internal:5432/prod",
+          { status: 500 }
+        )
+      )
+    );
+
+    try {
+      await apiJson("/items/1");
+      expect.unreachable("should have thrown");
+    } catch (thrown) {
+      expect(thrown).toBeInstanceOf(Response);
+      const res = thrown as Response;
+      expect(res.status).toBe(500);
+      expect(res.body).toBeNull();
+    }
+  });
+});

apps/arc-web/app/api-client.ts

@@ -51,6 +51,6 @@ export async function apiFetch(
  */
 export async function apiJson<T>(path: string, init?: RequestInit): Promise<T> {
   const res = await apiFetch(path, init);
-  if (!res.ok) throw new Response(await res.text(), { status: res.status });
+  if (!res.ok) throw new Response(null, { status: res.status });
   return res.json() as Promise<T>;
 }

apps/arc-web/package.json

@@ -6,6 +6,7 @@
     "build": "react-router build",
     "dev": "react-router dev",
     "start": "react-router-serve ./build/server/index.js",
+    "test": "ARC_API_BASE_URL=http://localhost:9999 bun test",
     "typecheck": "react-router typegen && tsc"
   },
   "dependencies": {

apps/arc-web/tsconfig.json

@@ -5,6 +5,7 @@
     "**/.client/**/*",
     ".react-router/types/**/*"
   ],
+  "exclude": ["**/*.test.ts"],
   "compilerOptions": {
     "lib": ["DOM", "DOM.Iterable", "ES2022"],
     "types": ["node", "vite/client"],

crates/arc-agent/README.md

@@ -9,7 +9,7 @@ The crate is organized around a central `Session` that drives an agentic loop:
 1. **User input** is appended to a conversation `History`
 2. The session builds a `Request` with system prompt, history, and tools
 3. An LLM generates a response (text and/or tool calls) via `unified-llm`
-4. Tool calls are executed through a `ToolRegistry` against an `Sandbox`
+4. Tool calls are executed through a `ToolRegistry` against a `Sandbox`
 5. Results are recorded and the loop continues until the LLM responds with text only (natural completion), a turn limit is reached, or the session is aborted
 
 ```

crates/arc-agent/src/cli.rs

@@ -382,7 +382,7 @@ pub async fn run_with_args(args: AgentArgs) -> anyhow::Result<()> {
     eprintln!("{}Using model: {model}{}", styles.dim, styles.reset,);
     let mut profile = build_profile(provider, model, Some(client.clone()));
 
-    // Build execution environment
+    // Build sandbox
     let cwd = std::env::current_dir().unwrap_or_else(|_| PathBuf::from("."));
     let cwd_str = cwd.to_string_lossy().to_string();
     let env: Arc<dyn crate::Sandbox> = Arc::new(LocalSandbox::new(cwd));

crates/arc-agent/src/docker_sandbox.rs

@@ -15,7 +15,7 @@ use std::collections::HashMap;
 use std::time::Instant;
 use tokio_util::sync::CancellationToken;
 
-/// Configuration for a Docker-based execution environment.
+/// Configuration for a Docker-based sandbox.
 pub struct DockerSandboxConfig {
     /// Docker image to use. Default: `"arc-agent:latest"`.
     pub image: String,
@@ -53,7 +53,7 @@ impl Default for DockerSandboxConfig {
     }
 }
 
-/// Execution environment that runs all operations inside a Docker container.
+/// Sandbox that runs all operations inside a Docker container.
 ///
 /// The host working directory is bind-mounted at `container_mount_point`. All file
 /// operations, commands, grep, and glob execute inside the container via `docker exec`.

crates/arc-agent/src/session.rs

@@ -170,7 +170,7 @@ impl Session {
         let today = chrono::Local::now().format("%Y-%m-%d").to_string();
         let model_name = self.provider_profile.model().to_string();
 
-        // Detect git info via execution environment
+        // Detect git info via sandbox
         let git_branch = self
             .sandbox
             .exec_command("git rev-parse --abbrev-ref HEAD", 5000, None, None, None)

crates/arc-agent/src/test_support.rs

@@ -199,7 +199,7 @@ impl Sandbox for MockSandbox {
 
 // --- MutableMockSandbox ---
 
-/// A mock execution environment with Mutex-protected files for tests that need
+/// A mock sandbox with Mutex-protected files for tests that need
 /// write operations to be visible to subsequent reads (e.g., `apply_patch` tests).
 pub struct MutableMockSandbox {
     pub files: Mutex<HashMap<String, String>>,

crates/arc-agent/src/v4a_patch.rs

@@ -124,7 +124,7 @@ pub fn parse_v4a_patch(text: &str) -> Result<Vec<PatchOperation>, String> {
     Ok(ops)
 }
 
-/// Applies a list of patch operations using the given execution environment.
+/// Applies a list of patch operations using the given sandbox.
 ///
 /// # Errors
 /// Returns an error if any file operation fails.

crates/arc-api/src/serve.rs

@@ -35,7 +35,7 @@ pub struct ServeArgs {
     #[arg(long)]
     pub dry_run: bool,
 
-    /// Execution environment for agent tools
+    /// Sandbox for agent tools
     #[arg(long, value_enum)]
     pub sandbox: Option<SandboxProvider>,
 

crates/arc-workflows/src/cli/mod.rs

@@ -110,7 +110,7 @@ pub struct RunArgs {
     #[arg(short, long, action = clap::ArgAction::Count)]
     pub verbose: u8,
 
-    /// Execution environment for agent tools
+    /// Sandbox for agent tools
     #[arg(long, value_enum)]
     pub sandbox: Option<SandboxProvider>,
 
@@ -868,10 +868,10 @@ pub fn format_event_detail(event: &WorkflowRunEvent, styles: &Styles) -> String
                     format!("{d}── SANDBOX_CLEANUP_FAILED ──────────────────{r}\n  {d}provider:{r} {provider}\n  {d}error:{r}    {error}\n")
                 }
                 SandboxEvent::SnapshotPulling { name } => {
-                    format!("{d}── SANDBOX_SNAPSHOT_PULLING ───────────────────{r}\n  {d}image:{r} {name}\n")
+                    format!("{d}── SANDBOX_SNAPSHOT_PULLING ───────────────────{r}\n  {d}name:{r} {name}\n")
                 }
                 SandboxEvent::SnapshotPulled { name, duration_ms } => {
-                    format!("{d}── SANDBOX_SNAPSHOT_PULLED ────────────────────{r}\n  {d}image:{r}       {name}\n  {d}duration_ms:{r} {duration_ms}\n")
+                    format!("{d}── SANDBOX_SNAPSHOT_PULLED ────────────────────{r}\n  {d}name:{r}       {name}\n  {d}duration_ms:{r} {duration_ms}\n")
                 }
                 SandboxEvent::SnapshotEnsuring { name } => {
                     format!("{d}── SANDBOX_SNAPSHOT_ENSURING ───────────────{r}\n  {d}name:{r} {name}\n")

crates/arc-workflows/src/cli/run.rs

@@ -376,7 +376,7 @@ pub async fn run_command(args: RunArgs, styles: &'static Styles) -> anyhow::Resu
         if let Ok(handle) = rt {
             handle.spawn(async move {
                 if let Err(e) = sandbox_for_cleanup.cleanup().await {
-                    tracing::warn!(error = %e, "Execution environment cleanup failed");
+                    tracing::warn!(error = %e, "Sandbox cleanup failed");
                     eprintln!("Warning: sandbox cleanup failed: {e}");
                 }
             });

crates/arc-workflows/src/handler/parallel.rs

@@ -16,7 +16,7 @@ use crate::outcome::{Outcome, StageStatus};
 use super::{EngineServices, Handler};
 
 // ---------------------------------------------------------------------------
-// WorktreeSandbox — decorates an Sandbox with a custom working dir
+// WorktreeSandbox — decorates a Sandbox with a custom working dir
 // ---------------------------------------------------------------------------
 
 /// Wraps an existing `Sandbox` so that all operations use a
@@ -256,7 +256,7 @@ impl Handler for ParallelHandler {
             None
         };
 
-        // Build per-branch sandboxs (sequentially for git setup)
+        // Build per-branch sandboxes (sequentially for git setup)
         struct BranchSetup {
             target_id: String,
             branch_index: usize,

crates/arc-workflows/tests/integration.rs

@@ -7608,10 +7608,10 @@ async fn large_context_values_are_offloaded_to_artifact_store() {
 }
 
 // ---------------------------------------------------------------------------
-// Artifact sync to remote execution environments
+// Artifact sync to remote sandboxs
 // ---------------------------------------------------------------------------
 
-/// A mock execution environment where `file_exists` always returns false,
+/// A mock sandbox where `file_exists` always returns false,
 /// simulating a remote container that doesn't have local artifact files.
 struct RemoteMockEnv {
     working_dir: String,
@@ -7924,7 +7924,7 @@ async fn node_dir_uses_visit_count_on_revisit() {
 
 use arc_workflows::cli::cli_backend::{BackendRouter, AgentCliBackend};
 
-/// A mock execution environment for CLI backend e2e tests.
+/// A mock sandbox for CLI backend e2e tests.
 /// Records all exec_command and write_file calls, and returns configurable
 /// responses based on command content.
 struct CliTestEnv {
@@ -8966,7 +8966,7 @@ use arc_workflows::engine::GitCheckpointMode;
 use arc_workflows::handler::fan_in::FanInHandler;
 use arc_workflows::handler::parallel::ParallelHandler;
 
-/// A handler that writes a file named `{node_id}.txt` into the execution environment's
+/// A handler that writes a file named `{node_id}.txt` into the sandbox's
 /// working directory. Used to verify git worktree isolation in parallel branches.
 struct FileWriterHandler;