refactor(parse-externals): drop babel for vendored acorn-wasm

Replaces @babel/parser + @babel/traverse + @babel/types in
src/ui/externals/parse-externals.ts with the vendored acorn-wasm
(Rust-built WASM acorn from ultrathink).

Bundle: 5.8 MB → 4.2 MB (-27%); sourcemap 3.6 MB → 524 KB.

Migration:
- @babel/parser → acorn-wasm.parse() (only used as a syntax-error
  sentinel; the AST itself is consumed via simple()).
- @babel/traverse → acorn-wasm.simple() (re-parses internally, plain
  ESTree-shape node visitor with no `path` wrapper).
- @babel/types `is*()` guards → ESTree `node.type === '...'` checks.
- Babel's `Literal`-family discrimination (StringLiteral /
  NumericLiteral / BigIntLiteral / RegExpLiteral / NullLiteral)
  collapses into ESTree's single `Literal` shape; we discriminate via
  `'regex' in node` / `'bigint' in node` / `typeof node.value`.
- ImportExpression visitor and CallExpression-with-callee.type ===
  'Import' both kept as defensive paths because acorn-wasm's emitted
  shape isn't strictly fixed across versions.

Locations:
- acorn-wasm doesn't surface `loc.{line,column}` on AST nodes — only
  byte `start`/`end` offsets. Built a lazy newline-offset table per
  source so offset → vscode.Position is O(log n) per lookup.

Workspace:
- Registered vendor/acorn-wasm as a pnpm workspace package
  (already named `acorn-wasm` in its package.json) and added it as
  a runtime dep via `acorn-wasm: workspace:*`. This way the import
  is `from 'acorn-wasm'` (a package name) rather than `from
  '../../../vendor/acorn-wasm/acorn-wasm-sync.mts'` (a relative
  `.mts` path that tsc/tsgo refuse without
  allowImportingTsExtensions).

Operator-map fallback:
- BinaryExpression / UnaryExpression now `?? kDYNAMIC_VALUE` so
  unrecognized operators (which the previous babel code couldn't
  hit thanks to typed enums) gracefully fall through to dynamic
  rather than producing `undefined` in the function-return type.

Removed deps: @babel/parser, @babel/traverse, @babel/types,
@types/babel__traverse.

Verified: pnpm install + check + test --all + build all green.
out/main.js bundle 4.2 MB. Test suite still passes (smoke).

Author: jdalton

package.json

@@ -114,17 +114,14 @@
     "vscode:uninstall": "node ./src/lifecycle/uninstall.mjs"
   },
   "dependencies": {
-    "@babel/parser": "7.29.3",
-    "@babel/traverse": "7.29.0",
-    "@babel/types": "7.29.0",
     "@socketsecurity/lib": "catalog:",
     "@vscode/python-extension": "1.0.6",
+    "acorn-wasm": "workspace:*",
     "ini": "6.0.0",
     "json-to-ast": "2.1.0",
     "toml-eslint-parser": "1.0.3"
   },
   "devDependencies": {
-    "@types/babel__traverse": "7.28.0",
     "@types/ini": "4.1.1",
     "@types/json-to-ast": "2.1.4",
     "@types/node": "catalog:",

pnpm-lock.yaml

@@ -5,8 +5,12 @@
 # Register .claude/hooks/* as workspace packages so taze (run via
 # `pnpm run update`) sees and bumps their package.json manifests
 # alongside the root. Keeps hook deps in lockstep with the parent.
+# vendor/acorn-wasm is registered too so the bundle imports it as a
+# package by name (acorn-wasm) rather than via a brittle relative
+# `.mts` path that tsc/tsgo refuse without allowImportingTsExtensions.
 packages:
   - .claude/hooks/*
+  - vendor/acorn-wasm
 
 # Catalog entries shared across hook workspaces. Pinning them here
 # keeps the entire hook tree in lockstep with the parent without each