feat: center square Hope presence and guide secure certificate setup

docs/ENGINEERING_LEARNINGS.md

@@ -29,6 +29,23 @@ Read [PROJECT_STATUS.md](PROJECT_STATUS.md) for the current product scope.
   logging at error. Offline auth fixtures use memory tokens, isolated preferences
   and deterministic no-network bootstrap errors.
 
+## Native certificate diagnosis and square presence — 2026-10-01
+
+- Match actual leaf and SPKI before changing a pin. Matching source pins do not
+  prove every SDK session uses the delegate; LiveKit owns a private system-trust
+  URLSession for WSS. App HTTPS probe passed physically; do not conflate a401 from
+  a deleted account with TLS failure or recreate unwanted test accounts.
+- Gate live TLS tests with explicit opt-in and print started/skipped scope; a test
+  returning early is not runtime proof. Regenerate XcodeGen for added test membership.
+  Physical test bundles require a development team override, not just app signing.
+- Certificate profiles require public-only verified data, user installation/full
+  trust, and persistent hosting. Copying a file into an active container is erased
+  at redeploy. Exact nginx alias may expose a public profile from cert mount; never
+  expose the directory containing the private key. Use apple profile MIME/no-store.
+- Canvas dot matrix is one accessible avatar, not441 focusable LEDs. Pause animation
+  when inactive and freeze audio geometry with Reduce Motion. Primary square remains
+  centered while active size/dynamic type leave space for transcript and controls.
+
 ## Preserve behavior across UI changes
 
 - Observe nested observable objects directly where their data is rendered. Watching