feat(chat): share a chat by link — anonymous read-only /shared/<token> page, share/unshare

app/main.py

@@ -21,7 +21,15 @@ from starlette.middleware.sessions import SessionMiddleware
 
 from app.api.auth import router as auth_router
 from app.api.chat import router as chat_router
-from app.api.chats import router as chats_router
+from app.api.chats import (
+    public_router as chats_public_router,
+)
+from app.api.chats import (
+    router as chats_router,
+)
+from app.api.chats import (
+    shared_page_router as chats_shared_page_router,
+)
 from app.api.config import router as config_router
 from app.api.docs import router as docs_router
 from app.api.git_sources import router as git_sources_router
@@ -73,6 +81,11 @@ def create_app() -> FastAPI:
     app.include_router(steering_router, prefix="/api")
     app.include_router(sync_router, prefix="/api")
     app.include_router(chats_router, prefix="/api")
+    # Phase 51: the anonymous shared-chat read — NO admin dependency.
+    # /api/shared/<token> is the JSON snapshot; /shared/<token> (the
+    # page route below, registered without a prefix) is the page.
+    app.include_router(chats_public_router, prefix="/api")
+    app.include_router(chats_shared_page_router)  # no prefix — /shared/<token>
 
     # Cache busting (phase 33): the five HTML pages revalidate (no-cache)
     # with ?v=<token> asset refs; /assets/* becomes immutable for a year.