Add zero-downtime deployment support with symlinks

[JoshSalway]

Summary

When deploying with symlink-based strategies (Deployer, Envoyer), Octane workers resolve the real path at startup and continue loading files from the old release directory after the symlink is switched. This means code changes are never picked up, even after octane:reload.

Fixes #1004

Problem

Octane workers call realpath() on the working directory at boot time. In symlink deployments, current -> releases/v1 resolves to /var/www/releases/v1. After deploying v2 and switching current -> releases/v2, octane:reload still resolves the cached real path, so workers continue serving v1 code.

/var/www/current -> /var/www/releases/v1  (before deploy)
/var/www/current -> /var/www/releases/v2  (after deploy)

# Octane worker still uses /var/www/releases/v1 because realpath() was cached

Solution

• Add ResolvesSymlinks trait that detects symlinked working directories and passes the logical path (not the resolved real path) to Swoole, RoadRunner, and FrankenPHP server processes
• Clear stat cache on octane:reload and Swoole beforeReload so symlinks are re-resolved
• Update Swoole bin scripts to use configurable bin directory via APP_RELEASE_BIN_DIR env var

Test Plan

• ResolvesSymlinksTest included covering symlink detection and path resolution
• Manual testing: deploy with Deployer using symlinked current directory, run octane:reload, verify new release code is loaded
• Non-symlinked deployments are unaffected (trait detects non-symlink and no-ops)

[github-actions]

Thanks for submitting a PR!

Note that draft PRs are not reviewed. If you would like a review, please mark your pull request as ready for review in the GitHub user interface.

Pull requests that are abandoned in draft may be closed due to inactivity.