fix(client,exporter): handle HTTP 429 retry and sanitize JSON

_get_with_retry now retries on HTTP 429 responses, respecting the
Retry-After header when present. exporter sanitizes control characters
(0x00-0x1F except \n \r \t) in text fields before JSON serialization.

fixes #11
fixes #12

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

src/gitea_dashboard/exporter.py

@@ -3,18 +3,38 @@
 from __future__ import annotations
 
 import json
+import re
 from dataclasses import asdict
 
 from gitea_dashboard.collector import RepoData
 
+# Caracteres de controle ASCII (0x00-0x1F) sauf \t (0x09), \n (0x0A), \r (0x0D)
+_CONTROL_CHAR_RE = re.compile(r"[\x00-\x08\x0b\x0c\x0e-\x1f]")
+
+
+def _sanitize_control_chars(text: str) -> str:
+    """Supprime les caracteres de controle ASCII (0x00-0x1F) sauf \\n, \\r et \\t.
+
+    Ces caracteres peuvent provenir de descriptions de repos Gitea
+    et causent des erreurs JSON ('Invalid control character').
+    """
+    return _CONTROL_CHAR_RE.sub("", text)
+
 
 def repos_to_dicts(repos: list[RepoData]) -> list[dict]:
     """Convertit une liste de RepoData en liste de dicts serialisables.
 
-    Chaque dict contient toutes les donnees du RepoData,
-    pret pour json.dumps().
+    Sanitize les champs texte (name, full_name, description) pour
+    supprimer les caracteres de controle invalides en JSON.
     """
-    return [asdict(repo) for repo in repos]
+    result = []
+    for repo in repos:
+        d = asdict(repo)
+        for field in ("name", "full_name", "description"):
+            if isinstance(d.get(field), str):
+                d[field] = _sanitize_control_chars(d[field])
+        result.append(d)
+    return result
 
 
 def export_json(repos: list[RepoData], indent: int = 2) -> str: