Janitorial: fix CLAUDE.md typos, remove stale notes and empty folder

- core/CLAUDE.md: fix ONBOARDING.md hyperlink (../), remove doubled
  "reasonable", fix "ifnsomething" and "bew toolchain" typos, remove
  human-note annotation
- core/AGENTS.md: drop stale payloads reference from module list
- core/src/payloads/: remove empty folder (only contained rename note)
- core/src/types/what was this.md: remove stale note (types are active)
- core/src/organs/soul/README-1ST.MD: update to reflect Ada already removed

Co-Authored-By: Claude <noreply@anthropic.com>

core/src/organs/soul/README-1ST.MD

@@ -1 +1 @@
-Claude really wanted a single language build, but thats not what we are doing. All Ada in this folder is defunct, and must be replaced.
+Ada sources formerly here have been removed. The soul organ (B2) is being rehomed — see `docs/plans/B2-soul-identity.md`.

core/src/payloads/rename this folder.md

@@ -1 +0,0 @@
-its a bad name

core/src/types/what was this.md

@@ -1 +0,0 @@
-unsure, was made uninvited