Performance & critical fixes: Redis, memory, SQL, indexes, CI gate

[frogr]

What

Comprehensive performance and safety fixes from the codebase audit. @frogr

Critical Fixes

• 🔴 Deploy gate — Deploys now require all CI jobs to pass first. Moved deploy job into ci.yml with needs: [scan_ruby, scan_js, lint, test]. Deleted standalone deploy.yml.
• 🔴 Redis connection leak — GpuJob was creating a new Redis.new() on every call. Now uses a shared memoized connection.
• 🔴 Memory bomb — tts_batches#download_all and stems#download_all loaded ALL base64 audio into memory for zip creation. Refactored to use temp files and find_each for streaming.

Performance Fixes

• SQL sort — Replaced Ruby sort_by with SQL ORDER BY COALESCE() in blog controllers
• Missing indexes — Added indexes on images.published, images.position, review_sections.status, reviews.pr_url
• Counter cache — Added story_paragraphs_count to stories (eliminates 2 COUNT queries per page load)
• Bulk insert — TTS batch creation uses insert_all! instead of N individual inserts
• Race condition — Invoice number generation now uses pg_advisory_lock to prevent duplicates
• N+1 protection — Added Client.with_invoice_totals for efficient list queries

Infrastructure

• Pinned Postgres 16 and Redis 7 in CI (were unpinned latest)

Verified

• bundle exec rubocop — 213 files, 0 offenses
• bin/rails test — 109 tests, 0 failures, 0 errors

Files changed (14)

M  .github/workflows/ci.yml
D  .github/workflows/deploy.yml
M  app/controllers/admin/blog_posts_controller.rb
M  app/controllers/blog_controller.rb
M  app/controllers/stems_controller.rb
M  app/controllers/tts_batches_controller.rb
M  app/jobs/gpu_job.rb
M  app/models/client.rb
M  app/models/invoice.rb
M  app/models/story.rb
M  app/models/story_paragraph.rb
A  db/migrate/20260317000001_add_missing_indexes.rb
A  db/migrate/20260317000002_add_story_paragraphs_count_to_stories.rb
M  db/schema.rb