fix: enrich SKILL.md docs to pass LLM evals, upgrade judge to Sonnet 4.6 (#43)

* fix: enrich command descriptions and snapshot flags for LLM eval quality

14 command descriptions enriched with specific arg formats, valid values,
error behavior, and return types. Fixed header usage from <name> <value>
to <name>:<value>. Added cookie usage syntax. Snapshot flags now show
long names, ref numbering, and output format examples.

* refactor: auto-generate server.ts help text from COMMAND_DESCRIPTIONS

Replace hand-maintained help block with generateHelpText() that reads
from COMMAND_DESCRIPTIONS and SNAPSHOT_FLAGS. Eliminates help text
drift from source of truth.

* test: add usage consistency and pipe guard tests

Usage consistency test cross-checks Usage: patterns in implementation
against COMMAND_DESCRIPTIONS using structural skeleton comparison.
Pipe guard test ensures descriptions don't contain | which would break
markdown table rendering.

* chore: upgrade eval judge to Sonnet 4.6, update changelog

Switch LLM-as-judge evals from Haiku to Sonnet 4.6 for more stable,
nuanced scoring. Add changelog entry for all eval improvements.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

test/gen-skill-docs.test.ts

@@ -139,6 +139,14 @@ describe('description quality evals', () => {
     }
   });
 
+  // Guard: descriptions must not contain pipe (breaks markdown table cells)
+  // Usage strings are backtick-wrapped in the table so pipes there are safe.
+  test('no command description contains pipe character', () => {
+    for (const [cmd, meta] of Object.entries(COMMAND_DESCRIPTIONS)) {
+      expect(meta.description).not.toContain('|');
+    }
+  });
+
   // Guard: generated output uses → not ->
   test('generated SKILL.md uses unicode arrows', () => {
     const content = fs.readFileSync(path.join(ROOT, 'SKILL.md'), 'utf-8');