ci: adopt estate CI standard — thin caller + wp-framework PHPUnit + 300-line split

- ci.yml: thin caller → peptide-e2e reusable (tests: wp-framework, has_js: true, line_limit_paths: inc)
- deploy.yml: retire standalone validate; gate deploy on ci.yml via workflow_call
- composer.json: test script → vendor/bin/phpunit (explicit)
- inc/helpers.php: split 311→211 lines; nav walker extracted to nav-walker.php
- inc/nav-walker.php: new — Peptide_Starter_Nav_Walker + menu fallback (123 lines)
- functions.php: require nav-walker.php before helpers.php; version 2.2.2→2.3.0
- style.css: version header 2.2.2→2.3.0
- package.json / package-lock.json: minimal npm manifest for lint-js job

Agent-Session: claude/adopt-ci-20260616

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ permissions:
 
 jobs:
   ci:
-    uses: peptide-repo/peptide-e2e/.github/workflows/ci.yml@main
+    uses: peptiderepo/peptide-e2e/.github/workflows/ci.yml@main
     with:
       tests: wp-framework
       has_js: true

.github/workflows/deploy.yml

@@ -4,9 +4,6 @@ on:
   push:
     branches: [main]
 
-permissions:
-  contents: write
-
 concurrency:
   group: deploy-peptide-starter-theme
   cancel-in-progress: true
@@ -18,12 +15,11 @@ jobs:
   # "ci / ci (lint-php (8.1))" etc.
   ci:
     uses: ./.github/workflows/ci.yml
-    secrets: inherit
 
   deploy:
     name: Deploy (shared pipeline)
     needs: ci
-    uses: peptide-repo/peptide-e2e/.github/workflows/deploy-app.yml@main
+    uses: peptiderepo/peptide-e2e/.github/workflows/deploy-app.yml@main
     with:
       target_path: wp-content/themes/peptide-starter
     secrets: inherit