docs(cli): remove duplicate docs/CLI-TOOLS.md + lint anti-regression

Phase 0.1 — single source of truth for CLI Tools documentation.

`docs/CLI-TOOLS.md` was a 492-line copy frozen at v3.0.0-rc.16 (13 tools,
outdated provider tables). The current source of truth is
`docs/reference/CLI-TOOLS.md` (v3.8.0, 17 tools, referenced by CLAUDE.md
and every cross-doc link in docs/).

Changes:
- delete docs/CLI-TOOLS.md (no remaining references; all docs already
  pointed at docs/reference/CLI-TOOLS.md)
- scripts/check/check-docs-sync.mjs: add anti-regression check that
  fails if a legacy superseded doc reappears

Verified: \`npm run check:docs-sync\` passes; rg shows zero remaining
references to the legacy path outside _references/ and _tasks/.

Refs: _tasks/features-v3.8.0/cli/fase-0-preparacao/0.1-limpar-docs-duplicada.md

scripts/check/check-docs-sync.mjs

@@ -244,6 +244,18 @@ try {
   checkI18nMirrorFile("llm.txt", llmPath);
   // CHANGELOG.md mirrors are translations — check version sections and size, not exact content
   checkI18nChangelogFile(changelogPath);
+
+  // Anti-regression: legacy duplicate docs that have been superseded must not return.
+  // Use docs/reference/* as the source of truth.
+  const supersededDocs = [{ legacy: "docs/CLI-TOOLS.md", current: "docs/reference/CLI-TOOLS.md" }];
+  for (const { legacy, current } of supersededDocs) {
+    const legacyAbs = path.resolve(cwd, legacy);
+    if (fs.existsSync(legacyAbs)) {
+      fail(
+        `legacy duplicate ${legacy} reappeared — use ${current} instead (single source of truth)`
+      );
+    }
+  }
 } catch (error) {
   fail(error instanceof Error ? error.message : String(error));
 }