Add QR pairing (terminal QR, in-app scanner, iris://pair deep link)

docs/15-hermes-reference.md

@@ -5,7 +5,7 @@ integration point. Paths are relative to `hermes-agent/` (the read-only
 reference). This lets a coder jump straight to the right code instead of
 re-deriving the architecture.
 
-> ⚠️ Read-only. We **install** our plugin into `~/.hermes/plugins/android`; we
+> ⚠️ Read-only. We **install** our plugin into `~/.hermes/plugins/iris`; we
 > never edit these files.
 
 ## Plugin / platform registration