chore: move business tooling out of the public library; tidy filestore naming

Keep the public tree project-generic. Business/one-off tools, deployment
and business docs move to the private oo-workspace repo.

Moved to oo-workspace:
- cmd/ooscan, cmd/pdfamount, cmd/kontoblatt, cmd/kontolink
- internal/xlspipe (cutover-portugal workbook) -> oow workbook build
  (drops the --template/--title flags from oo docs put-xlsx)
- deploy/docker-compose.rclone-webdav.yml + docs/rclone-webdav.md
- docs/crm-associations.md

Removed GitHub-era leftovers:
- .github/workflows/release-please.yml, release-please-config.json,
  .release-please-manifest.json (tags are created on Gitea per SemVer)

Naming: the FileStore subsystem is now filestore_*.go (was file_*.go) to
match files_*.go (project Documents). Docs/AGENTS/README updated.

storage_fallback.go

@@ -163,7 +163,7 @@ func (c *Client) downloadFromMinio(ctx context.Context, objectKey string, dst io
 
 // downloadMinioObject streams objectKey from the configured MinIO bucket using
 // hc. It is the shared implementation behind (*Client).downloadFromMinio and
-// the read-only SQL store (file_pg.go), which has no *Client.
+// the read-only SQL store (filestore_pg.go), which has no *Client.
 func downloadMinioObject(ctx context.Context, hc *http.Client, objectKey string, dst io.Writer) (int64, error) {
 	if objectKey == "" {
 		return 0, fmt.Errorf("onlyoffice: minio fallback: empty object key")