fix: use cross-platform temp paths for Windows CI compatibility

Replace hardcoded /tmp/ paths with std::env::temp_dir() in:
- scheduler/coordinator.rs (raft WAL test)
- sandbox/wasm.rs (WASM sandbox tests)
- agent/config.rs (default work_dir)
- cli/submitter.rs (submit test)

Fixes Windows CI failure: raft_storage_with_wal panicked on /tmp path.

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

Author: jeremymanning

src/agent/config.rs

@@ -23,7 +23,7 @@ pub struct AgentConfig {
 impl Default for AgentConfig {
     fn default() -> Self {
         Self {
-            work_dir: PathBuf::from("/tmp/worldcompute"),
+            work_dir: std::env::temp_dir().join("worldcompute"),
             cpu_cap_percent: 80,
             storage_cap_bytes: 10 * 1024 * 1024 * 1024, // 10 GB
             otel_endpoint: None,

src/cli/submitter.rs

@@ -75,8 +75,10 @@ mod tests {
 
     #[test]
     fn submit_returns_manifest_path_in_message() {
-        let msg = execute(&JobCommand::Submit { manifest_path: "/tmp/job.json".into() });
-        assert!(msg.contains("/tmp/job.json"));
+        let test_path = std::env::temp_dir().join("job.json");
+        let test_path_str = test_path.to_string_lossy().to_string();
+        let msg = execute(&JobCommand::Submit { manifest_path: test_path_str.clone() });
+        assert!(msg.contains(&test_path_str));
     }
 
     #[test]

src/sandbox/wasm.rs

@@ -204,15 +204,15 @@ mod tests {
     #[test]
     fn wasm_engine_initializes() {
         let store = CidStore::new();
-        let sandbox = WasmSandbox::new(std::path::PathBuf::from("/tmp/wc-test-wasm"), store);
+        let sandbox = WasmSandbox::new(std::env::temp_dir().join("wc-test-wasm"), store);
         assert!(sandbox.is_ok());
     }
 
     #[test]
     fn wasm_create_fails_for_missing_cid() {
         let store = CidStore::new();
         let mut sandbox =
-            WasmSandbox::new(std::path::PathBuf::from("/tmp/wc-test-wasm-missing"), store).unwrap();
+            WasmSandbox::new(std::env::temp_dir().join("wc-test-wasm-missing"), store).unwrap();
         let cid = crate::data_plane::cid_store::compute_cid(b"nonexistent").unwrap();
         assert!(sandbox.create(&cid).is_err());
     }
@@ -224,7 +224,7 @@ mod tests {
         let cid = store.put(&wasm_bytes).unwrap();
 
         let mut sandbox =
-            WasmSandbox::new(std::path::PathBuf::from("/tmp/wc-test-wasm-run"), store).unwrap();
+            WasmSandbox::new(std::env::temp_dir().join("wc-test-wasm-run"), store).unwrap();
         assert!(sandbox.create(&cid).is_ok());
         assert!(sandbox.start().is_ok());
         assert!(sandbox.terminate().is_ok());
@@ -237,7 +237,7 @@ mod tests {
         let cid = store.put(bad_bytes).unwrap();
 
         let mut sandbox =
-            WasmSandbox::new(std::path::PathBuf::from("/tmp/wc-test-wasm-bad"), store).unwrap();
+            WasmSandbox::new(std::env::temp_dir().join("wc-test-wasm-bad"), store).unwrap();
         let result = sandbox.create(&cid);
         assert!(result.is_err());
         assert!(result.unwrap_err().to_string().contains("compilation failed"));
@@ -250,8 +250,7 @@ mod tests {
         let cid = store.put(&wasm_bytes).unwrap();
 
         let mut sandbox =
-            WasmSandbox::new(std::path::PathBuf::from("/tmp/wc-test-wasm-lifecycle"), store)
-                .unwrap();
+            WasmSandbox::new(std::env::temp_dir().join("wc-test-wasm-lifecycle"), store).unwrap();
         assert!(sandbox.create(&cid).is_ok());
         assert!(sandbox.start().is_ok());
         assert!(sandbox.freeze().is_ok());

src/scheduler/coordinator.rs

@@ -446,7 +446,7 @@ mod tests {
 
     #[test]
     fn raft_storage_with_wal() {
-        let wal_path = std::path::PathBuf::from("/tmp/wc-test-raft-wal.json");
+        let wal_path = std::env::temp_dir().join("wc-test-raft-wal.json");
         let mut storage = RaftCoordinatorStorage::with_wal(wal_path.clone());
         let entry = RaftLogEntry { term: 1, index: 1, action: CoordinatorAction::Noop };
         assert!(storage.append(entry).is_ok());