Sweep surveillance vocabulary from owner-facing docs
Apply system-anatomy canon to README, INSTALL, AGENTS. Lead with
"observers" / "experiences along with" / "observations" in branded
prose. Preserve all internal-architecture and code-identifier uses
of `capture` (Capture Loop heading, capture.py module, captures/
on-disk path, capture_interval config key). Add a Brand canon
pointer section in AGENTS.md mirroring the solstone-linux precedent.