fix(cache): clean up stale output archives on cache update

Each cache update writes a fresh UUID-named archive into the cache
directory; the previous archive for the same key was being abandoned
on disk, causing the cache directory to grow unboundedly with each
re-execution of a cached task.

`ExecutionCache::update` now reads the prior entry and removes the
old archive file (best-effort) before upserting the new value.

Also:
- restore alphabetical ordering for `zstd` in the workspace Cargo.toml
  and `uuid` in `vite_task/Cargo.toml`
- add a CHANGELOG entry for the new `output` field

Author: claude

CHANGELOG.md

@@ -1,5 +1,6 @@
 # Changelog
 
+- **Added** `output` field for cached tasks: archives output files after a successful run and restores them on cache hit. Defaults to automatically tracking files the task writes; accepts globs (e.g. `"dist/**"`), `{ "auto": true }`, and negative patterns (`"!dist/cache/**"`) ([#321](https://github.com/voidzero-dev/vite-task/pull/321))
 - **Fixed** `vp run --cache` now supports running without a task specifier and opens the interactive task selector, matching bare `vp run` behavior ([#312](https://github.com/voidzero-dev/vite-task/pull/313))
 - **Fixed** Ctrl-C now prevents future tasks from being scheduled and prevents caching of in-flight task results ([#309](https://github.com/voidzero-dev/vite-task/pull/309))
 - **Added** `--concurrency-limit` flag to limit the number of tasks running at the same time (defaults to 4) ([#288](https://github.com/voidzero-dev/vite-task/pull/288), [#309](https://github.com/voidzero-dev/vite-task/pull/309))

Cargo.toml

@@ -136,7 +136,6 @@ tui-term = "0.3.1"
 twox-hash = "2.1.1"
 uuid = "1.18.1"
 vec1 = "1.12.1"
-zstd = "0.13"
 vite_glob = { path = "crates/vite_glob" }
 vite_graph_ser = { path = "crates/vite_graph_ser" }
 vite_path = { path = "crates/vite_path" }
@@ -155,6 +154,7 @@ widestring = "1.2.0"
 winapi = "0.3.9"
 winsafe = { version = "0.0.24", features = ["kernel"] }
 xxhash-rust = { version = "0.8.15", features = ["const_xxh3"] }
+zstd = "0.13"
 
 [workspace.metadata.cargo-shear]
 ignored = [

crates/vite_task/Cargo.toml

@@ -36,13 +36,13 @@ tokio = { workspace = true, features = ["rt-multi-thread", "io-std", "io-util",
 tokio-util = { workspace = true }
 tracing = { workspace = true }
 twox-hash = { workspace = true }
+uuid = { workspace = true, features = ["v4"] }
 vite_path = { workspace = true }
 vite_select = { workspace = true }
 vite_str = { workspace = true }
 vite_task_graph = { workspace = true }
 vite_task_plan = { workspace = true }
 vite_workspace = { workspace = true }
-uuid = { workspace = true, features = ["v4"] }
 wax = { workspace = true }
 zstd = { workspace = true }
 

crates/vite_task/src/session/cache/mod.rs

@@ -274,16 +274,33 @@ impl ExecutionCache {
     }
 
     /// Update cache after successful execution.
+    ///
+    /// If a previous entry exists for the same cache key with a different
+    /// `output_archive`, the stale archive file in `cache_dir` is removed
+    /// (best-effort) so it doesn't accumulate on disk.
     #[tracing::instrument(level = "debug", skip_all)]
     pub async fn update(
         &self,
         cache_metadata: &CacheMetadata,
         cache_value: CacheEntryValue,
+        cache_dir: &AbsolutePath,
     ) -> anyhow::Result<()> {
         let execution_cache_key = &cache_metadata.execution_cache_key;
 
         let cache_key = CacheEntryKey::from_metadata(cache_metadata);
 
+        // If a previous entry exists with a stale output archive, delete the
+        // old file so the cache directory doesn't accumulate orphaned archives.
+        if let Some(old_value) = self.get_by_cache_key(&cache_key).await?
+            && let Some(old_archive) = old_value.output_archive
+            && cache_value.output_archive.as_ref() != Some(&old_archive)
+        {
+            let old_archive_path = cache_dir.join(old_archive.as_str());
+            // Best-effort cleanup: a missing file (e.g. after a crash or manual
+            // cache clear) is fine, so we ignore the error.
+            let _ = std::fs::remove_file(old_archive_path.as_path());
+        }
+
         self.upsert_cache_entry(&cache_key, &cache_value).await?;
         self.upsert_task_fingerprint(execution_cache_key, &cache_key).await?;
         Ok(())

crates/vite_task/src/session/execute/mod.rs

@@ -532,7 +532,7 @@ pub async fn execute_spawn(
                                 globbed_inputs,
                                 output_archive,
                             };
-                            match cache.update(cache_metadata, new_cache_value).await {
+                            match cache.update(cache_metadata, new_cache_value, cache_dir).await {
                                 Ok(()) => (CacheUpdateStatus::Updated, None),
                                 Err(err) => (
                                     CacheUpdateStatus::NotUpdated(