docs: align ADR path references to doc/adr (singular)

Mirror of factory#8 path correction. Updates Gitea URLs in AUTH.md /
HOWTO_ADD_BOT.md and the '// Voir factory/...' header comments in code.

chart/templates/deployment.yaml

@@ -45,7 +45,7 @@ spec:
               value: ":{{ .Values.service.port }}"
             - name: CONFIG_PATH
               value: /etc/telegram-gateway/bots.yaml
-            # Auth layer — voir factory/docs/adr/20260509-telegram-gateway-auth.md.
+            # Auth layer — voir factory/doc/adr/20260509-telegram-gateway-auth.md.
             # AUTH_SECRET et ALLOWED_USERS arrivent via envFrom secretRef.
             - name: REDIS_URL
               value: {{ .Values.auth.redisURL | quote }}

chart/values.yaml

@@ -82,7 +82,7 @@ autoscaling:
 # Bot routing config — non-secret, becomes the bots.yaml ConfigMap entry.
 # Tokens & secret_token values live in a k8s Secret named `secret.name`.
 #
-# Auth gate (Phase 1.5, ADR factory/docs/adr/20260509-telegram-gateway-auth.md):
+# Auth gate (Phase 1.5, ADR factory/doc/adr/20260509-telegram-gateway-auth.md):
 #   - `requireAuth` defaults to **true** (secure by default). Add
 #     `requireAuth: false` only for bots you want to expose publicly.
 #   - For `handler: auth`, requireAuth is auto-forced to false (the auth bot