Documentation that points where the documentation is

The working notes, the roadmap and the eight topic notes now live on the wiki,
so the twelve places in the source that said "see CLAUDE.md" were pointing at
a file this repository no longer has. They say "see the working notes" now,
and the README opens onto the wiki rather than onto two files beside it.

Four references are deliberately untouched -- prompts.py, settings_store.py,
admin/agents.html and the whole of agent/instructions.py. Those name AGENTS.md
and CLAUDE.md as the file an agent chat looks for in *somebody else's* project
directory. Rewriting them would have broken the feature while looking tidy.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/lembas/api/chats.py

@@ -985,7 +985,7 @@ def _too_many_replies(db: DBSession, chat: Chat, user: User) -> str:
     """Why this account may not start another reply right now, or "".
 
     In-process, and that is exact rather than approximate only because this
-    application runs one worker -- see the first known limit in PLAN.md. With
+    application runs one worker -- see the first known limit in the roadmap. With
     several, this becomes a guess, and a quota that is a guess should be a
     number in the database instead. Stated here rather than discovered.
     """