feat(migration/msg): port 3 self-contained msg types (megaport STEP 8 follow-up) (#74)

Ports 3 src/msg/*.res files that are truly self-contained (no
cross-module `open Model` or `XxxModel.foo` qualified-path refs):

- OrbitalMsg.affine        (8 LoC) — pure sum type
- FeedbackMsg.affine       (11 LoC) — sum with Result<String,String>
- VideoCoordinationMsg.affine (11 LoC) — sum with Result<String,String>

All 3 pass `affinescript check`. Total: 30 LoC of .res ported.

These are the only currently-portable msg files; the other ~119 msg/
files all either `open Model` or use qualified `XxxModel.fooTab`
types — both blocked on affinescript#228 (in-tree qualified paths
in non-stdlib context).

Adjacent to panll#72 (the 11 src/modules/ ports). Same megaport
STEP 8 context, different subdirectory.

Refs standards#279 (megaport STEP 8), standards#252 (campaign UMBRELLA).

Author: hyperpolymath

migration/msg/FeedbackMsg.affine

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell
+//
+// FeedbackMsg.affine — Feedback-O-Tron messages (user feedback submission
+// lifecycle).
+//
+// Translation of src/msg/FeedbackMsg.res (11 LoC). Pure sum-type module
+// using `Result<String, String>` from prelude. No cross-module msg/model
+// dep.
+//
+// Refs: standards#279 (megaport STEP 8).
+
+module FeedbackMsg;
+
+use prelude::{Result, Ok, Err};
+
+type FeedbackMsg =
+  | OpenFeedback
+  | SubmitFeedback(String)
+  | CancelFeedback
+  | SetReportType(String)
+  | FeedbackSubmitted
+  | FeedbackSubmissionResult(Result<String, String>)

migration/msg/OrbitalMsg.affine

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell
+//
+// OrbitalMsg.affine — orbital stability messages (stability, divergence,
+// drift aura).
+//
+// Translation of src/msg/OrbitalMsg.res (8 LoC). Pure sum-type module
+// — no cross-module deps, no Tea_/Promise/FFI surface. The cleanest
+// possible Mode-A port in panll's src/msg/ tree.
+//
+// Refs: standards#279 (megaport STEP 8).
+
+module OrbitalMsg;
+
+type OrbitalMsg =
+  | UpdateStability(Float)
+  | UpdateDivergence(Float)
+  | SetDriftAura(String)

migration/msg/VideoCoordinationMsg.affine

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (c) 2026 Jonathan D.A. Jewell
+//
+// VideoCoordinationMsg.affine — messages for the VideoCoordination panel
+// (Drive-to-Photos batch transfers).
+//
+// Translation of src/msg/VideoCoordinationMsg.res (11 LoC). Pure sum-type
+// module using `Result<String, String>` from prelude.
+//
+// Refs: standards#279 (megaport STEP 8).
+
+module VideoCoordinationMsg;
+
+use prelude::{Result, Ok, Err};
+
+type VideoCoordinationMsg =
+  | StartTransfer(String, String)
+  | PauseTransfer(String)
+  | RefreshStatus
+  | StatusResult(Result<String, String>)
+  | TransferResult(Result<String, String>)
+  | ClearError