web-app-taiga: add manage/init flow and idempotent admin bootstrap; fix OIDC config and env quoting

config/main.yml: convert oidc from empty mapping to block; indent flavor under oidc; enable javascript feature.

tasks/main.yml: use path_join for taiga settings; create docker-compose-inits via TAIGA_DOCKER_COMPOSE_INIT_PATH; flush handlers; add idempotent createsuperuser via taiga-manage with async/poll and masked logs.

templates/docker-compose-inits.yml.j2: include compose/container base to inherit env and project settings.

templates/env.j2: quote WEB_PROTOCOL and WEBSOCKET_PROTOCOL.

templates/javascript.js.j2: add SSO warning include.

users/main.yml: add administrator email stub.

vars/main.yml: add js_application_name; restructure OIDC flavor flags; add compose PATH vars; expose TAIGA_SUPERUSER_* vars.

Chat reference: https://chatgpt.com/share/68af7637-225c-800f-b670-2b948f5dea54

roles/web-app-taiga/config/main.yml

@@ -1,10 +1,10 @@
-oidc: {}
+oidc:
     # Taiga doesn't have a functioning oidc support at the moment
     # See
     # - https://community.taiga.io/t/taiga-and-oidc-plugin/4866
     #
     # Due to this reason this plutin is deactivated atm
-flavor:               'taigaio' # Potential flavors: robrotheram, taigaio
+  flavor:             'taigaio' # Potential flavors: robrotheram, taigaio
 features:
   matomo:             true
   css:                true
@@ -12,6 +12,7 @@ features:
   oidc:               false
   central_database:   true
   logout:             true
+  javascript:         true
 docker:
   services:
     database: