Fix stale docblocks, a todo typo, and the paths in .env.dist and zensical.toml

Problem/Motivation

Five small things say something wrong:

• The SseState::collection() docblock says the store is resolved before the stream's first yield. ApiSseController::sse() yields first, and the store is resolved on the first read after it. It works because KeepSessionOpenEventStreamResponse keeps the session open.
• InstanceTranslationSubscriber says param conversion runs at priority 5000 on kernel.request. 5000 is the priority of the route enhancer. Conversion runs in the router listener, at 32.
• TextareaWidget has @toto for @todo.
• .env.dist names PlaywrightTestSetup.php. The file is DisplayBuilderTestSetup.php.
• zensical.toml sets edit_uri on main. The branch is 1.0.x, so the edit links of the docs site point to a branch that does not exist.

Proposed resolution

Fix the comments and the two paths. No behavior change.

User interface changes

None. The edit links of the docs site work again.

API changes

None.

Data model changes

None.