Update website loader/chunker to web page loader/chunker

revert

- Add user identity to extraction preamble so memories are attributed to
  the correct user instead of cross-referencing cached patterns (OPE-6 #1)
- Skip mem0.add() when no user messages remain after noise filtering,
  avoiding wasted API calls on assistant-only payloads (OPE-6 #2)
- Raise auto-recall threshold to 0.6 (vs 0.5 for explicit search) and
  add dynamic thresholding that drops memories below 50% of the top
  result's score to reduce irrelevant context injection (OPE-6 #3)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

- Add user identity to extraction preamble so memories are attributed to
  the correct user instead of cross-referencing cached patterns (OPE-6 #1)
- Skip mem0.add() when no user messages remain after noise filtering,
  avoiding wasted API calls on assistant-only payloads (OPE-6 #2)
- Raise auto-recall threshold to 0.6 (vs 0.5 for explicit search) and
  add dynamic thresholding that drops memories below 50% of the top
  result's score to reduce irrelevant context injection (OPE-6 #3)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

- Add user identity to extraction preamble so memories are attributed to
  the correct user instead of cross-referencing cached patterns (OPE-6 #1)
- Skip mem0.add() when no user messages remain after noise filtering,
  avoiding wasted API calls on assistant-only payloads (OPE-6 #2)
- Raise auto-recall threshold to 0.6 (vs 0.5 for explicit search) and
  add dynamic thresholding that drops memories below 50% of the top
  result's score to reduce irrelevant context injection (OPE-6 #3)

Co-Authored-By: Claude Opus 4.6 <[email protected]>

- require_admin: handle ADMIN_API_KEY and AUTH_DISABLED on fresh empty DB
  by falling through to allow bootstrap when no users exist yet, instead
  of raising 401 (Finding #1)
- docker-compose healthcheck: use ${POSTGRES_USER:-postgres} instead of
  hardcoded -U postgres so custom POSTGRES_USER values work (Finding #2)
- require_admin: restore request: Request param (needed for auth_type
  check) but now used in function body (Finding #7 resolved)
- docs: sync migration guide password placeholder with README (Finding #9)