feat(runner-protocol): IPC protocol + Rust transport

Add three new crates that together define the runner-tool IPC:

- `vite_task_ipc_shared` — message types + wire format shared by both
  ends. Spawned tools tell the runner what they read, wrote, or cared
  about; the runner uses that to decide what to fingerprint in the
  cache.
- `vite_task_server` — async server hosted in the runner. One server
  instance per task execution.
- `vite_task_client` — synchronous blocking client used by spawned
  tools. The sync API is deliberate: most tools are JS, called
  one-method-at-a-time, and don't want a runtime imposed on them.

The two sides are wired together end-to-end in
`vite_task_server/tests/integration.rs`, so this PR is independently
reviewable as "does the wire format and transport work correctly?"
without depending on runner internals.

Design notes: `docs/runner-task-ipc/`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: wan9chi

Cargo.lock

@@ -80,6 +80,7 @@ fspy_shared = { path = "crates/fspy_shared" }
 fspy_shared_unix = { path = "crates/fspy_shared_unix" }
 futures = "0.3.31"
 futures-util = "0.3.31"
+interprocess = "2"
 jsonc-parser = { version = "0.32.0", features = ["serde"] }
 libc = "0.2.185"
 libtest-mimic = "0.8.2"
@@ -149,8 +150,11 @@ vite_shell = { path = "crates/vite_shell" }
 vite_str = { path = "crates/vite_str" }
 vite_task = { path = "crates/vite_task" }
 vite_task_bin = { path = "crates/vite_task_bin" }
+vite_task_client = { path = "crates/vite_task_client" }
 vite_task_graph = { path = "crates/vite_task_graph" }
+vite_task_ipc_shared = { path = "crates/vite_task_ipc_shared" }
 vite_task_plan = { path = "crates/vite_task_plan" }
+vite_task_server = { path = "crates/vite_task_server" }
 vite_workspace = { path = "crates/vite_workspace" }
 vt100 = "0.16.2"
 wax = "0.7.0"
@@ -168,6 +172,10 @@ ignored = [
   # These are artifact dependencies. They are not directly `use`d in Rust code.
   "fspy_preload_unix",
   "fspy_preload_windows",
+  # Registered in the workspace dependency table so downstream PRs in the
+  # runner-aware-tools stack can pick it up via `workspace = true` without
+  # touching this file. No in-tree consumer in this PR.
+  "vite_task_server",
 ]
 
 [profile.dev]

Cargo.toml

@@ -37,7 +37,7 @@ use wincode::{
 /// **Not portable across platforms.** The binary representation is platform-specific.
 /// Deserializing a `NativeStr` serialized on a different platform leads to unspecified
 /// behavior (garbage data), but is not unsafe. Designed for same-platform IPC only.
-#[derive(TransparentWrapper, PartialEq, Eq)]
+#[derive(TransparentWrapper, PartialEq, Eq, PartialOrd, Ord)]
 #[repr(transparent)]
 pub struct NativeStr {
     // On unix, this is the raw bytes of the OsStr.

crates/native_str/src/lib.rs

@@ -0,0 +1,21 @@
+[package]
+name = "vite_task_client"
+version = "0.0.0"
+edition.workspace = true
+license.workspace = true
+publish = false
+rust-version.workspace = true
+
+[dependencies]
+interprocess = { workspace = true }
+native_str = { workspace = true }
+vite_path = { workspace = true }
+vite_task_ipc_shared = { workspace = true }
+wincode = { workspace = true, features = ["derive"] }
+
+[lints]
+workspace = true
+
+[lib]
+doctest = false
+test = false

crates/vite_task_client/Cargo.toml

@@ -0,0 +1,3 @@
+# vite_task_client
+
+IPC client that connects from tool processes to the task runner to report inputs/outputs, request env values, and disable caching.