docs(code-runtime): fix remaining dunder/backend wording and document exports in README

- index.ts: RESERVED_ERROR_MEMBERS JSDoc now says `__x__` (non-empty
  middle), matching DUNDER_MEMBER and the derivative docs; and
  PORTABLE_RESERVED_WORDS is described as covering portable *target*
  languages (Python is a later-PR backend, not yet shipped).
- types.ts + type-equiv docs: CodeBindingNamespace.global points to
  RESERVED_BINDING_GLOBALS by name with an `e.g.` sample rather than
  enumerating the set (single home), no longer implying `__debug__` is a
  seeded slot.
- Agent Note: separate `__debug__` (CPython compile-time constant) from
  the seeded bootstrap globals.
- README (en/zh): document the four exported exclusion sets and the
  portable identifier/naming contract — no cross-package link needed.
- Regenerate cordis services catalog for the shifted source line.

packages/code-runtime/code-runtime/src/index.ts

@@ -48,10 +48,10 @@ export const RESERVED_BINDING_GLOBALS: ReadonlySet<string> = new Set([
  * one shared contract so a request valid on one backend is valid on all. The
  * JS `Error` exclusions (`name`, `message`, `stack`) and Python's
  * exception-protocol members (`args`, `with_traceback`, `add_note`) are
- * listed by name; dunder-form names (`__*__`) are refused wholesale — several
- * are constrained CPython descriptors whose `setattr` raises while
- * constructing the rejection, and the exact set is an interpreter version
- * detail. Any other non-empty own property name is accepted everywhere.
+ * listed by name; dunder-form names (`__x__`, non-empty middle) are refused
+ * wholesale — several are constrained CPython descriptors whose `setattr`
+ * raises while constructing the rejection, and the exact set is an interpreter
+ * version detail. Any other non-empty own property name is accepted everywhere.
  */
 export const RESERVED_ERROR_MEMBERS: ReadonlySet<string> = new Set([
   'name', 'message', 'stack',
@@ -65,9 +65,11 @@ export const RESERVED_ERROR_MEMBERS: ReadonlySet<string> = new Set([
 export const DUNDER_MEMBER = /^__.+__$/
 
 /**
- * Reserved words of EVERY shipped backend language (ECMAScript ∪ Python),
+ * Reserved words of every portable target language (ECMAScript ∪ Python),
  * refused as {@link CodeBindingNamespace.global} / error-class names by all
- * backends. The portable-identifier contract promises a namespace list valid
+ * backends. Python is a portability target here even though only the
+ * TypeScript worker ships in this PR (the CPython backend is a later PR in the
+ * stack). The portable-identifier contract promises a namespace list valid
  * on one backend is valid on every backend; a per-language check would let
  * `lambda` pass the TypeScript backend and fail the Python one. Extending the
  * seam with a new language means widening this union (a breaking review of