feat(dashboard): add milestone view and configurable columns

fixes #16, fixes #19

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

src/gitea_dashboard/exporter.py

@@ -6,7 +6,7 @@ import json
 import re
 from dataclasses import asdict
 
-from gitea_dashboard.collector import RepoData
+from gitea_dashboard.collector import MilestoneData, 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]")
@@ -44,3 +44,23 @@ def export_json(repos: list[RepoData], indent: int = 2) -> str:
         Chaine JSON indentee, prete pour stdout ou ecriture fichier.
     """
     return json.dumps(repos_to_dicts(repos), indent=indent, ensure_ascii=False)
+
+
+def milestones_to_dicts(milestones: list[MilestoneData]) -> list[dict]:
+    """Convertit une liste de MilestoneData en liste de dicts serialisables.
+
+    Sanitize les champs texte (repo_name, title) pour les caracteres de controle.
+    """
+    result = []
+    for ms in milestones:
+        d = asdict(ms)
+        for field in ("repo_name", "title"):
+            if isinstance(d.get(field), str):
+                d[field] = _sanitize_control_chars(d[field])
+        result.append(d)
+    return result
+
+
+def export_milestones_json(milestones: list[MilestoneData], indent: int = 2) -> str:
+    """Exporte les milestones en JSON formate."""
+    return json.dumps(milestones_to_dicts(milestones), indent=indent, ensure_ascii=False)