feat: HTTP-over-iroh proxy in tunnel + convergence fixtures pass

Jazz leaves proxy their catalogue (schema/permissions) HTTP reads and
writes to their upstream, so the tunnel now carries plain HTTP alongside
the sync WebSocket: HELLO{kind:'http',method,path,headers} + body frame
up, {status,headers} + body back, one request per iroh conn.

Convergence fixtures (lofi's two-device offline-edit pattern from
access_sync_test): pass against a hosted daemon, an in-memory node, and
the full topology — device A on the root, device B on a leaf paired over
iroh, concurrent offline edits converge across the tunnel (~1s).

Also: UUID appIds (Jazz requires them), $createdBy permissions policy,
ws:// URL normalization, /health as the liveness probe, shutdown errors
logged instead of crashing the SIGINT handler.

commit

765ec197acb4203cd9efae6037bc4e9fda8b91e1

parent

19245e3cd8ab8601c74b73479709f420c90ded92

author

Dami <dami.etoile@gmail.com>