docs: reconcile LESSONS.md and VISION.md with what the branch removed

- LESSONS.md's 2026-06-22 test-placement entry told authors to put test
  files directly in scripts/ with a README row. The file-structure contract
  the repo now enforces permits tests/ as one of four directories, requires
  a tests/README.md when it exists, and FAILs test files in scripts/.
- LESSONS.md's 2026-08-16 entry described a dispatch chain ending at
  skill-author/references/retrofit.md in the present tense. This branch
  deleted that file. Sibling entries whose referents the branch removed
  were marked historical; this one was not.
- VISION.md's Phase 1 now puts stack, framework and deployment choices out
  of scope for this repo, while Phase 3 still named React Native and Tauri.

README.md was checked and needed no change: its offline guarantee already
carries the populated-apm_modules condition from 8cfd54f and agrees with
gates.md and AGENTS.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NwD8Egs5r4ndqeFLmhusX2

docs/VISION.md

@@ -60,4 +60,4 @@ Runtime orchestration: push config updates to machines, see running agents, mana
 
 ### Phase 3 — Native Apps
 
-Mobile (React Native) and desktop (Tauri) wrappers over the Phase 1/2 web app. Deferred until the web app is mature.
+Mobile and desktop wrappers over the Phase 1/2 web app. Deferred until the web app is mature; the wrapper technology is that product's own choice, on the same terms as the rest of its stack.