Annotate UI: allow embedded hosts to skip the permission-mode setup dialog

[ddiall]

The annotate UI shows a one-time "Permission Mode Preservation" setup dialog
(Auto-accept Edits / Auto Mode / Bypass / Manual) for any unconfigured origin.

This dialog belongs to Claude Code plan-mode hook semantics. When the UI is
embedded in a host app (iframe) or driven by a non-hook client, it is pure
friction with no meaning — and because the choice persists per origin
(host:port), it reappears whenever the port changes or embedded storage is
partitioned.

Proposal: an env flag (e.g. PLANNOTATOR_SKIP_PERMISSION_SETUP=1) or query
param that suppresses the dialog; or skip it when the origin is not a hook
integration. Happy to implement — please confirm the trigger path
(PermissionModeSetup in the editor) and bless the flag name.

[ddiall]

We're integrating Plannotator's annotate UI into the Hermes Agent desktop app (via its plugin SDK — an embedded pane with the session in an iframe). This dialog is the single biggest friction point for us: it is Claude-hook-specific, and because it persists per origin, embedding hosts see it on every session (each port is a new origin). A skip flag would give hosts like ours a clean first-run surface. Happy to contribute the patch — and we can bring the Hermes-side integration as a reference consumer if that helps validate the approach.