chore: keep host/client specifics out of the tree (env & config)

Showroom-safe: the tree no longer carries internal hosts, IPs, ports,
personal names, client domains or client file names. Behaviour is
unchanged and now supplied per deployment.

- catalog: hardcoded mail-org / project classifiers become a YAML-driven
  Classifier (OO_CATALOG_CONFIG or --config); neutral default classifies
  nothing as work. New catalog/classify.go + example + tests.
- storage_fallback: drop the baked-in MinIO endpoint IP; require
  MINIO_ENDPOINT (+ keys) from the env.
- kontolink: build DocEditor links from $ONLYOFFICE_URL instead of a
  hardcoded portal host; kontoblatt: no client file id in the output name.
- oo: load .env CLI-wide (bootstrap.LoadEnv in execute) so
  non-authenticating commands (catalog scans) also see config.
- genericize comments/docs/fixtures (AGENTS, README, .env.example,
  crm-associations, catalog tests, ES/pdfattach tests, mails).

.env.example

@@ -34,13 +34,18 @@ ONLYOFFICE_PROJECT_ID=33
 
 # MinIO download fallback for the portal's stale AWS S3 consumer (older
 # Documents folders). When the portal redirects to amazonaws.com with access
-# key "minio" (403 InvalidAccessKeyId), files are fetched from the local MinIO
-# store instead. Without a key/secret the fallback is disabled.
-# MINIO_ENDPOINT=http://192.168.188.10:9000
+# key "minio" (403 InvalidAccessKeyId), files are fetched from the configured
+# MinIO store instead. Without endpoint + key/secret the fallback is disabled.
+# MINIO_ENDPOINT=http://minio.example.com:9000
 # MINIO_BUCKET=office
 # MINIO_ACCESS_KEY=
 # MINIO_SECRET_KEY=
 
+# Catalog scan classification rules (client mail domains, project remotes/names).
+# Copy catalog/classify.example.yaml and point this at it; no rules means
+# nothing is classified as work.
+# OO_CATALOG_CONFIG=~/.config/oo/catalog-classify.yaml
+
 # oo search — direct Elasticsearch access for name + content search. ES lives
 # inside the OnlyOffice VM on localhost:9200; expose it with an SSH tunnel
 # (see docs/elasticsearch.md). ONLYOFFICE_ES_INDEX defaults to files_file.