feat(palier-1): journal d'événements, détail d'issue, vieillissement, WIP

- board_events append-only + log_event/get_events/column_entry_times/
  get_metrics (débit, temps de cycle); journalisation des moves,
  créations, fermetures/rouvertures (UI et réconciliation Gitea),
  commentaires; un reclassement intra-colonne ne journalise pas
- client Gitea: get_issue, get_issue_comments (paginés), create_comment
- API: GET /api/issues/{o}/{r}/{n} (404 propre), POST .../comments,
  GET /api/events, GET /api/metrics, page /activity
- config: KANBANTE_WIP_LIMITS (colonne:limite) et KANBANTE_AGING_DAYS;
  le board calcule le temps en colonne (journal, replis updated_at
  puis création de l'issue)
- reconcile_board_state retourne aussi les numéros fermés/purgés

app/config.py

@@ -17,6 +17,12 @@ Environment variables:
     KANBANTE_MAX_NOTE_CHARS      Maximum size of a project note (default 20000).
     KANBANTE_SYNC_GITEA          "1" (default) = moving a card to/from "done"
                                  closes / reopens the Gitea issue.
+    KANBANTE_WIP_LIMITS          Comma list "column:limit" (e.g.
+                                 "in_progress:5,review:3"). Columns not
+                                 listed are unlimited. Soft limits: the UI
+                                 warns, moves are never blocked.
+    KANBANTE_AGING_DAYS          Days in the same column before a card is
+                                 flagged as aging (default 7; "stale" at 2x).
 """
 
 import os
@@ -25,7 +31,7 @@ from pathlib import Path
 
 BASE_DIR = Path(__file__).resolve().parent.parent
 
-APP_VERSION = "0.2.0"
+APP_VERSION = "0.3.0"
 
 
 def _env_bool(name: str, default: bool) -> bool:
@@ -51,6 +57,16 @@ def _env_float(name: str, default: float) -> float:
         return default
 
 
+def _env_wip_limits(name: str) -> dict[str, int]:
+    limits: dict[str, int] = {}
+    for chunk in os.getenv(name, "").split(","):
+        column, sep, value = chunk.partition(":")
+        column = column.strip()
+        if sep and column and value.strip().isdigit():
+            limits[column] = int(value.strip())
+    return limits
+
+
 @dataclass(frozen=True)
 class Settings:
     gitea_url: str = "https://git.dracodev.net"
@@ -63,6 +79,8 @@ class Settings:
     cache_ttl: float = 30.0
     max_note_chars: int = 20_000
     sync_gitea: bool = True
+    wip_limits: dict | None = None
+    aging_days: int = 7
 
     @property
     def auth_enabled(self) -> bool:
@@ -84,4 +102,6 @@ def get_settings() -> Settings:
         cache_ttl=_env_float("KANBANTE_CACHE_TTL", 30.0),
         max_note_chars=_env_int("KANBANTE_MAX_NOTE_CHARS", 20_000),
         sync_gitea=_env_bool("KANBANTE_SYNC_GITEA", True),
+        wip_limits=_env_wip_limits("KANBANTE_WIP_LIMITS"),
+        aging_days=_env_int("KANBANTE_AGING_DAYS", 7),
     )