feat(config): static vite config extraction for run config (#679)

Add new `vite_static_config` crate that uses `oxc_parser` to statically
extract JSON-serializable fields from `vite.config.*` files without
executing JavaScript

## Performance

Measured using Chrome trace instrumentation (PR #663).

On a cache hit, `vp run` loads the config, validates the fingerprint,
and streams cached output — no build work. Before this PR, config
loading required a NAPI round-trip to evaluate the config file. With
static extraction that cost drops to ~0ms.

### `vp run` end-to-end time (cache hit)

| Project | Before | After | Reduction |
|---------|--------|-------|-----------|
| vue-mini | ~217ms | **23ms** | ~89% |
| oxlint-plugin-complexity | ~220ms | **17ms** | ~92% |
| vitepress | ~282ms | **32ms** | ~89% |
| vite-vue-vercel | ~326ms | **28ms** | ~91% |
| rollipop | ~670ms | **16–53ms** | ~92–98% |
| frm-stack (10 packages) | ~895ms | **34–69ms** | ~92–96% |
| tanstack-start-helloworld | ~1,383ms | ~1,394ms | — (indirect export,
not yet handled) |

## Summary

- `VitePlusConfigLoader` now tries static extraction first for the `run`
config, falling back to NAPI-based resolution only when the config
cannot be statically extracted
- Static extraction supports all common patterns:
  - `export default { ... }` — bare object literal
  - `export default defineConfig({ ... })` — direct call
  - `export default defineConfig(() => ({ ... }))` — concise arrow body
  - `export default defineConfig(fn)` — block body with single return
  - `module.exports = ...` — CJS equivalents
- When no `vite.config.*` file exists, returns an empty map immediately
(skips NAPI entirely)
- Spread and computed-key properties correctly invalidate
previously-seen fields

## Test plan
- [x] 50 unit tests in `vite_static_config` pass
- [x] All existing `vite-plus-cli` tests pass
- [x] `cargo fmt --check` passes
- [x] `cargo shear` reports no unused dependencies
- [x] `cargo clippy` clean (no new warnings)
- [ ] CI passes on all platforms

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: branchseer

Cargo.lock

@@ -187,6 +187,7 @@ vite_glob = { git = "ssh://git@github.com/voidzero-dev/vite-task.git", rev = "6f
 vite_install = { path = "crates/vite_install" }
 vite_migration = { path = "crates/vite_migration" }
 vite_shared = { path = "crates/vite_shared" }
+vite_static_config = { path = "crates/vite_static_config" }
 vite_path = { git = "ssh://git@github.com/voidzero-dev/vite-task.git", rev = "6fdc4f106563491be4fb36381b84c5937d74fe9c" }
 vite_str = { git = "ssh://git@github.com/voidzero-dev/vite-task.git", rev = "6fdc4f106563491be4fb36381b84c5937d74fe9c" }
 vite_task = { git = "ssh://git@github.com/voidzero-dev/vite-task.git", rev = "6fdc4f106563491be4fb36381b84c5937d74fe9c" }
@@ -211,7 +212,10 @@ oxc = { version = "0.115.0", features = [
   "cfg",
 ] }
 oxc_allocator = { version = "0.115.0", features = ["pool"] }
+oxc_ast = "0.115.0"
 oxc_ecmascript = "0.115.0"
+oxc_parser = "0.115.0"
+oxc_span = "0.115.0"
 oxc_napi = "0.115.0"
 oxc_minify_napi = "0.115.0"
 oxc_parser_napi = "0.115.0"

Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "vite_static_config"
+version = "0.0.0"
+authors.workspace = true
+edition.workspace = true
+homepage.workspace = true
+license.workspace = true
+repository.workspace = true
+
+[dependencies]
+oxc_allocator = { workspace = true }
+oxc_ast = { workspace = true }
+oxc_parser = { workspace = true }
+oxc_span = { workspace = true }
+rustc-hash = { workspace = true }
+serde_json = { workspace = true }
+vite_path = { workspace = true }
+
+[dev-dependencies]
+tempfile = { workspace = true }
+
+[lints]
+workspace = true

crates/vite_static_config/Cargo.toml

@@ -0,0 +1,58 @@
+# vite_static_config
+
+Statically extracts configuration from `vite.config.*` files without executing JavaScript.
+
+## What it does
+
+Parses vite config files using [oxc_parser](https://crates.io/crates/oxc_parser) and extracts
+top-level fields whose values are pure JSON literals. This allows reading config like `run`
+without needing a Node.js runtime (NAPI).
+
+## Supported patterns
+
+**ESM:**
+
+```js
+export default { run: { tasks: { build: { command: "echo build" } } } }
+export default defineConfig({ run: { cacheScripts: true } })
+```
+
+**CJS:**
+
+```js
+module.exports = { run: { tasks: { build: { command: 'echo build' } } } };
+module.exports = defineConfig({ run: { cacheScripts: true } });
+```
+
+## Config file resolution
+
+Searches for config files in the same order as Vite's
+[`DEFAULT_CONFIG_FILES`](https://github.com/vitejs/vite/blob/25227bbdc7de0ed07cf7bdc9a1a733e3a9a132bc/packages/vite/src/node/constants.ts#L98-L105):
+
+1. `vite.config.js`
+2. `vite.config.mjs`
+3. `vite.config.ts`
+4. `vite.config.cjs`
+5. `vite.config.mts`
+6. `vite.config.cts`
+
+## Return type
+
+`resolve_static_config` returns `Option<FxHashMap<Box<str>, FieldValue>>`:
+
+- **`None`** — config is not statically analyzable (no config file, parse error, no
+  `export default`/`module.exports`, or the exported value is not an object literal).
+  Caller should fall back to runtime evaluation (e.g. NAPI).
+- **`Some(map)`** — config object was successfully located:
+  - `FieldValue::Json(value)` — field value extracted as pure JSON
+  - `FieldValue::NonStatic` — field exists but contains non-JSON expressions
+    (function calls, variables, template literals with interpolation, etc.)
+  - Key absent — field does not exist in the config object
+
+## Limitations
+
+- Only extracts values that are pure JSON literals (strings, numbers, booleans, null,
+  arrays, and objects composed of these)
+- Fields with dynamic values (function calls, variable references, spread operators,
+  computed properties, template literals with expressions) are reported as `NonStatic`
+- Does not follow imports or evaluate expressions