- Update ci.yml to run on PRs to both dev and main branches
- Add release-rc.yml workflow for automatic RC builds on dev merges
  - Creates versioned RC tags (e.g., 1.55.0-rc.abc1234)
  - Pushes dev-latest tag for bleeding edge users
- Update release.yml to auto-trigger on main merges (not just manual dispatch)
  - Keeps dry_run option for testing
  - Adds skip-ci check to prevent loops

Closes #378

- Add branching strategy section explaining dev → main flow
- Update PR process to target dev branch instead of main
- Document RC builds on dev merges and production releases on main merges
- Add Docker tag reference table for each branch type
- Update code review checklist to include dev branch targeting

- Fix bug where YOUTARR_IMAGE was always overwritten (now respects .env value)
- Add --dev CLI flag to use dialmaster/youtarr:dev-latest image
- Show warning when using dev builds about stability
- Update print_usage() with --dev flag documentation
- Add 'Using Development Builds' section to README.md with:
  - Instructions for --dev flag usage
  - Manual YOUTARR_IMAGE configuration for non-script users
  - How to switch back to stable builds

Shows context-aware names in Actions UI:
- 'Production Release — Auto' for push-triggered releases
- 'Production Release — Manual' for workflow_dispatch
- 'Production Release — Dry Run' for dry run mode

…udit logging, URL length validation

…hing-workflow

Implement dev branch workflow with RC builds

The previous format (1.55.0-rc.<sha>) implied the RC was for a specific
version, when it's actually just the current state of dev. The new format
(dev-rc.<sha>) makes it clear these are dev branch builds, not tied to
any particular release version.

…hing-workflow

fix: change RC tag format from version-based to dev-rc.<sha>

The version check now excludes dev-latest and dev-rc.* tags when
determining the latest stable version. This prevents users on stable
builds from seeing update notifications for dev builds.

- Filter out tags starting with 'dev' in getCurrentReleaseVersion
- Add test to verify dev tags are properly filtered

…hing-workflow

fix: filter dev tags from version update notification

Add API keys for external integrations on single video downloads

fix: allow CORS preflight for bookmarklets behind external auth proxies