port: pin Godot 4.7.2, and decide the MCP/skills question

The pin was 4.3, chosen without checking; 4.7.2 is the current stable (released
2026-08-18). Getting this right matters more here than usual because the project
diffs Godot screenshots against a reference renderer, so the engine version is
part of the measurement.

No Godot MCP server. Not because they are bad -- the mature ones need a LIVE
editor plus a WebSocket plugin and a Python server, which is a daemon, an editor
process and a second runtime added to an unattended loop. And their headline
feature, scene-tree introspection and node manipulation, is built for someone
hand-authoring scenes in the editor. This port GENERATES screens from exported
JSON: the agent writes a loader, not a scene tree, so the feature that justifies
the complexity does not apply. What it actually needs to verify itself -- run
headless, screenshot, diff against sylpheed-cli screen render -- is already a
bash job.

Third-party skill packs are the opposite trade: pure context, no runtime. Worth
revisiting, deliberately not installed now, because a skill is instructions
injected into an agent running with approvals disabled -- a supply-chain
decision, not a default -- and because P0/P1 need no advanced GDScript. The
agent may propose one, naming the milestone it unblocks, for a human to vendor
and review.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

docker/Dockerfile

@@ -38,7 +38,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 # Pinned. An engine version bump changes rendering, and this project compares
 # screenshots against a reference renderer — so an upgrade must be a deliberate,
 # stated act rather than a silent drift.
-ARG GODOT_VERSION=4.3
+ARG GODOT_VERSION=4.7.2
 RUN cd /tmp \
     && curl -fsSLO "https://github.com/godotengine/godot/releases/download/${GODOT_VERSION}-stable/Godot_v${GODOT_VERSION}-stable_linux.x86_64.zip" \
     && unzip -q "Godot_v${GODOT_VERSION}-stable_linux.x86_64.zip" \

docs/MISSION.md

@@ -115,3 +115,41 @@ Only the boot intro and the one new-game intro are in scope. The disc holds
 3D, gameplay, HUD, missions, save/load, localisation beyond English, the Ready
 Room, and any reverse engineering. If you want an answer the disc has not given
 you, that is a request to the container agent, not a task for you.
+
+## 8. Tooling policy — MCP servers and third-party skills
+
+Surveyed 2026-08-28. **No Godot MCP server, for now**, and the reason is not
+that they are bad:
+
+* The mature ones ([godot-ai][ga], and most of the field) need a **live Godot
+  editor** running with a plugin that talks WebSocket to a Python server. This
+  agent is headless in a container; that is a daemon, an editor process and a
+  second language runtime added to an unattended loop, all of which can fail in
+  ways that look like a port bug.
+* Their headline feature is **scene-tree introspection and node manipulation** —
+  built for someone hand-authoring scenes in the editor. This port *generates*
+  its screens from exported JSON at runtime. The agent writes a loader, not a
+  scene tree, so the feature that justifies the complexity does not apply here.
+* What the agent actually needs to verify its work already exists:
+  `godot-headless` to run the project and `screenshot` to diff against
+  `sylpheed-cli screen render`. The verification loop is the valuable part, and
+  it is a bash job.
+
+**Third-party skill packs** ([godot-claude-skills][gcs], [GodotPrompter][gp],
+[Godot-Claude-Skills][rcs]) are the opposite trade: pure context, no runtime, no
+daemon. They are worth revisiting. They are **not installed now** because a skill
+is *instructions injected into an agent running with approvals disabled*, which
+is a supply-chain decision and not one to make by default — and because P0/P1 are
+a Rust exporter and a static sprite draw, which need no advanced GDScript.
+
+**If you want one, propose it**: name the pack, say which milestone it unblocks,
+and let a human vendor and review it. Do not install from a marketplace on your
+own authority.
+
+Revisit this if GDScript quality becomes the bottleneck — most likely at P2,
+where keyframe ramps meet tweens.
+
+[ga]: https://github.com/hi-godot/godot-ai
+[gcs]: https://github.com/alexmeckes/godot-claude-skills
+[gp]: https://github.com/jame581/GodotPrompter
+[rcs]: https://github.com/Randroids-Dojo/Godot-Claude-Skills