refactor: rebrand decp.info to colibre #57

- Rename project from decp.info to colibre across all codebase
- Update domain from https://decp.info to https://colibre.fr
- Update GitHub repo references to ColinMaudry/colibre
- Rename deployment files: decpinfo-backup.* → colibre-backup.*
- Update project configuration and documentation
- Rename project assets: decp.info.png → colibre.png
- Update environment variables and constants (DOMAIN_NAME, TOKEN_PREFIX, GITHUB_REPO, etc.)
- Update URLs in all pages, tests, and configuration files
- Keep DECP acronym in text (unchanged per requirements)
- Add rebrand note to README.md

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

src/subscriptions/plans.py

@@ -17,7 +17,7 @@ PLANS = {
         "env": "FRISBII_PLAN_SIMPLE",
         "label": "Abonnement",
         "prix_ht": 20,
-        "description": "Accès aux fonctionnalités supplémentaires de decp.info.",
+        "description": "Accès aux fonctionnalités supplémentaires de colibre.",
     },
     "soutien": {
         "env": "FRISBII_PLAN_SOUTIEN",