feat(config-audit): remove TOK Pattern D detectSonnetEra (v5 F5)

Pattern D was the v4 sonnet-era signature: 'config is structurally
clean but uses no Opus-4.7-specific features'. Two problems:
- It triggered on any minimal config that happened to lack skills/MCP
- The advice was generic and not actionable

The hotspots ranking and per-pattern findings (A/B/C) cover the same
ground with concrete, file-anchored signal. Dropping the noise.

BREAKING (intentional): scanners no longer emit the sonnet-era info
finding. Suppression entries and downstream tooling that reference
the v4 finding ID should be updated. Doc sweep follows in Step 8b.

Tests: sonnet-era fixture now asserts zero findings.

plugins/config-audit/tests/scanners/token-hotspots.test.mjs

@@ -87,15 +87,20 @@ describe('TOK scanner — opus-47/deep-imports', () => {
   });
 });
 
-describe('TOK scanner — opus-47/sonnet-era', () => {
+describe('TOK scanner — opus-47/sonnet-era (v5 F5: Pattern D removed)', () => {
   let result;
   beforeEach(async () => {
     result = await runScanner('opus-47/sonnet-era');
   });
 
-  it('emits no findings above info severity', () => {
-    const nonInfo = result.findings.filter(f => f.severity !== 'info');
-    assert.equal(nonInfo.length, 0, `expected only info findings, got: ${nonInfo.map(f => f.id + '=' + f.severity).join(', ')}`);
+  it('emits zero findings (no Pattern D / CA-TOK-004 anymore)', () => {
+    assert.equal(result.findings.length, 0,
+      `expected 0 findings on sonnet-era after F5, got: ${result.findings.map(f => f.id).join(', ')}`);
+  });
+
+  it('never emits CA-TOK-004 (removed in v5)', () => {
+    assert.ok(result.findings.every(f => f.id !== 'CA-TOK-004'),
+      'expected no CA-TOK-004; removed in v5 F5');
   });
 });