Fix services.memory bullet-list extraction by grouping the bullet/number regex before the capture, and cover both memory manager copies in the regression test.
The fallback memory extractor (used by routes/memory_routes.py when the LLM
extractor fails) matched list items with `r'^[-*•]|\d+\.\s*(.*)'`. Operator
precedence makes that `(^[-*•]) | (\d+\.\s*(.*))`, so the capture group only
exists on the numbered-list branch.
A bullet line ("- foo") matches the first branch, so `group(1)` is None and
`text_match.group(1).strip()` raises AttributeError — crashing extraction for
any assistant message that contains a bullet list (i.e. most of them). Numbered
lists happened to work.
Group both markers — `r'^(?:[-*•]|\d+\.)\s*(.*)'` — so the capture applies to
bullets and numbers alike.
Adds tests/test_memory_bullet_extraction.py (red before, green after).
