Use `str.removeprefix()` instead of character-set stripping so
subloggers such as `piker.paper` retain their requested namespace.
Also,
- drop stale parent-logger assertions from daemon startup paths
- keep logger setup calls without assigning assertion-only locals
- cover both logger factories and prefix-sensitive module names
Prompt-IO: ai/prompt-io/opencode/20260821T042058Z_b7aca4c0_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))