fix(ci): align the CLAUDE.md contract with the symlink, unbreaking main

[edheltzel]

main is red. 5336d5f ("claude.md is a symlink to agents.md") changed CLAUDE.md to a symlink but left the test and docs asserting the old @AGENTS.md shim.

(fail) CLAUDE.md is a shim that @-imports AGENTS.md (no duplicated content)
Expected substring or pattern: /^@AGENTS\.md\s*$/m

5336d5f = CI failure · 58cb1d1 = success. This unblocks it.

Why both assertions broke

Reading CLAUDE.md now follows the link and returns all of AGENTS.md, so:

• expect(body).toMatch(/^@AGENTS\.md\s*$/m) — the import line no longer exists
• expect(body).not.toContain('.agents/atlas/artifacts/') — it does now; that's AGENTS.md's own content

The fix: assert the link, not the content

The contract being defended is unchanged — "CLAUDE.md must never carry a second copy of the guide." A symlink satisfies it by construction: there is literally one file, so content cannot drift. A content assertion here would just be asserting AGENTS.md against itself.

const link = lstatSync(join(repoRoot, 'CLAUDE.md'));
expect(link.isSymbolicLink()).toBe(true);
expect(readlinkSync(join(repoRoot, 'CLAUDE.md'))).toBe('AGENTS.md');
expect(read('CLAUDE.md')).toBe(read('AGENTS.md'));

Plus a guard for the symlink's real failure mode

With core.symlinks=false (a common Windows default), git materializes CLAUDE.md as a plain file whose entire content is the literal string AGENTS.md — and Claude Code would load that as the whole guide, silently, with no error. The @-import shim had no such failure mode, so this risk is new and worth a test:

test('CLAUDE.md did not degrade into a literal-path text file', () => {
  const body = read('CLAUDE.md');
  expect(body.trim()).not.toBe('AGENTS.md');
  expect(body).toContain('.agents/atlas/artifacts/');
});

Scope note: this affects contributors only. The CLAUDE.md Recall installs for users is generated from templates/CLAUDE.md.template and is untouched by this.

Docs realigned

They described a mechanism that no longer exists:

• AGENTS.md:3, :37, :105 — "thin shim that @-imports" → "symlink"
• AGENTS.md → Agent Context Files — documents the symlink, the /init hazard (now "replaces the symlink with a copy"), and the core.symlinks=false limitation
• docs/releasing.md pre-flight — this mattered: it told maintainers to run cat CLAUDE.md and confirm it prints "the @AGENTS.md import — nothing else." That now prints the entire guide, so the pre-flight would fail every release. Changed to ls -l CLAUDE.md (expects CLAUDE.md -> AGENTS.md); recovery is ln -sf AGENTS.md CLAUDE.md.

Verification

tests/commands/scout-workflow.test.ts: 27 pass / 0 fail. bun run lint clean. New pre-flight command verified against the real file:

$ ls -l CLAUDE.md
lrwxr-xr-x  CLAUDE.md -> AGENTS.md

Blocks #242 and the v0.9.4 patch release — merge this first.