chore: remove all gitea remote references; single origin push only

There is only one remote (origin). Removed all occurrences of:
  - git push gitea / git push origin main && git push gitea main
  - "Pushing to gitea (external)" in deploy.sh
  - # gitea: git@gitea.meghsakha.com:... remote comment in docs-src/index.md
  - "Push auf gitea triggert" → "Push auf origin triggert" in docs
  - Clone URL updated to ssh://git@coolify.meghsakha.com:22222/... in
    README.md and CONTRIBUTING.md

Web UI URLs (gitea.meghsakha.com/...) are unchanged — those are still valid.

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

CONTRIBUTING.md

@@ -5,7 +5,7 @@
 ## 1. Getting Started
 
 ```bash
-git clone https://gitea.meghsakha.com/Benjamin_Boenisch/breakpilot-compliance.git
+git clone ssh://git@coolify.meghsakha.com:22222/Benjamin_Boenisch/breakpilot-compliance.git
 cd breakpilot-compliance
 git checkout coolify        # always base work off coolify, NOT main
 ```