Add chat-ui-htmx module: streaming chat page on Spring AI 2.0.2 with htmx and its SSE extension (vendored), MessageChatMemoryAdvisor keyed by the HTTP session, a Stop button, and the traps measured: EventSource strips one leading space per data line, model text must be HTML-escaped, a cancelled stream left the upstream connection open in 7 of 8 runs until an OkHttp interceptor calls Call.cancel (8 of 8 closed after), and the SDK push source ignores back-pressure (limitRate changes only the demand; a bounded buffer works). The model is a stub OpenAI-compatible SSE server written for the module; no real provider was run.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_017ic4b6Kg9RWSTJzyz6KP9X

chat-ui-htmx/output/01-sse-transcript.txt

@@ -0,0 +1,24 @@
+$ GET /chat/stream?message=hello world   (raw lines, first 14 and last 5)
+event:token
+data: [stub]
+
+event:token
+data:  saw
+
+event:token
+data:  2
+
+event:token
+data:  messages.
+
+event:token
+data:  Earlier
+...
+data:  world
+<blank>
+event:done
+data:
+<blank>
+event names seen: [token, done]
+joined token text as EventSource delivers it: [stub] saw 2 messages. Earlier user turns: none. You said: hello world
+same text if the server did not pad:        [stub]saw2messages.Earlieruserturns:none.Yousaid:helloworld