Publish Claude Code source snapshot from a single baseline commit

Squash the imported source snapshot and follow-up documentation history
into one root commit so the archive starts from a single coherent state.

Constraint: Repository intentionally tracks an analyzed Claude Code source snapshot
Constraint: Author and committer must be instructkr <no-contact@instruct.kr>
Rejected: Preserve the four-step import/docs history | user explicitly requested one squashed commit
Confidence: high
Scope-risk: broad
Reversibility: clean
Directive: Keep future analysis and refactor commits separate from this archive baseline
Tested: git status clean; local history rewritten to one commit; force-pushed main to origin and instructkr
Not-tested: Fresh clone verification after push

src/cli/ndjsonSafeStringify.ts

@@ -0,0 +1,32 @@
+import { jsonStringify } from '../utils/slowOperations.js'
+
+// JSON.stringify emits U+2028/U+2029 raw (valid per ECMA-404). When the
+// output is a single NDJSON line, any receiver that uses JavaScript
+// line-terminator semantics (ECMA-262 §11.3 — \n \r U+2028 U+2029) to
+// split the stream will cut the JSON mid-string. ProcessTransport now
+// silently skips non-JSON lines rather than crashing (gh-28405), but
+// the truncated fragment is still lost — the message is silently dropped.
+//
+// The \uXXXX form is equivalent JSON (parses to the same string) but
+// can never be mistaken for a line terminator by ANY receiver. This is
+// what ES2019's "Subsume JSON" proposal and Node's util.inspect do.
+//
+// Single regex with alternation: the callback's one dispatch per match
+// is cheaper than two full-string scans.
+const JS_LINE_TERMINATORS = /\u2028|\u2029/g
+
+function escapeJsLineTerminators(json: string): string {
+  return json.replace(JS_LINE_TERMINATORS, c =>
+    c === '\u2028' ? '\\u2028' : '\\u2029',
+  )
+}
+
+/**
+ * JSON.stringify for one-message-per-line transports. Escapes U+2028
+ * LINE SEPARATOR and U+2029 PARAGRAPH SEPARATOR so the serialized output
+ * cannot be broken by a line-splitting receiver. Output is still valid
+ * JSON and parses to the same value.
+ */
+export function ndjsonSafeStringify(value: unknown): string {
+  return escapeJsLineTerminators(jsonStringify(value))
+}