fix(repo): escape raw NUL bytes that hid six source files from grep (#3127)

Six source files embedded a literal U+0000 byte as a composite-key
separator instead of the `\u0000` escape. grep/ripgrep scan the whole
buffer, classify such a file as binary, and silently return no matches:
`grep -n saveMetaItem protocol.ts` reported nothing despite 16 hits,
making a core protocol file invisible to code search and to any
grep-based lint tooling.

This survived review because git only scans the first 8000 bytes for a
NUL, and protocol.ts carried its NUL at offset 147230 - so the file kept
diffing as ordinary text while grep had already given up on it.

Replace each raw NUL with `\u0000`, matching the existing convention in
rest-server.ts. That form is chosen over `\0`, which becomes a legacy
octal escape error if it is ever followed by a digit.

The resulting strings are byte-identical, so behaviour is unchanged:
getMetaItemCached still emits the same per-locale ETags as before
(en-US 68f978ed / zh-CN 50289f3b / no-locale 75dad1ef), still returns
304 on a same-locale match, and still declines 304 across locales
(issue #1319). No changeset: pure fix, no user-facing change.

Co-authored-by: Jack Zhuang <277994282+os-zhuang@users.noreply.github.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: os-zhuang

packages/cli/src/utils/lint-view-refs.ts

@@ -3051,7 +3051,7 @@ export class ObjectStackProtocolImplementation implements ObjectStackProtocol {
             // language until a hard refresh (issue #1319). Folding the resolved
             // locale into the hash gives each locale a distinct validator.
             const content = JSON.stringify(item);
-            const hash = simpleHash(request.locale ? `${request.locale}
+            const hash = simpleHash(request.locale ? `${request.locale}\u0000${content}` : content);
             const etag = { value: hash, weak: false };
 
             // Check If-None-Match header