Add flight-map-canvas extension (#2482)

* Add flight-map-canvas extension

A canvas port of the Flight Map VSCode extension: a first-person
satellite terrain map flown with flight simulator controls, for
session breaks while an agent works.

The simulator under game/ is copied verbatim from the source
extension's media/ folder. That page already reached its host through
one seam - an acquireVsCodeApi() object and a placeholder in its head -
so extension.mjs fills that seam for the canvas: a loopback server that
injects a policy, the render configuration, and a shim translating
Server-Sent Events into the messages the page already handles.

Two agent actions: fly_to sends the flight to a capital, a geocoded
city, or a raw lat/lng, and picks a random capital when called with no
input; report_job shows the current job step under the HUD.

Adds the vendored three.min.js to the codespell skip list, matching the
existing entry for arcade-canvas's phaser.min.js.

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

* Apply suggestions from code review

---------

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

extensions/flight-map-canvas/.github/plugin/plugin.json

@@ -0,0 +1,20 @@
+{
+  "name": "flight-map-canvas",
+  "description": "A GitHub Copilot canvas that generates a view where Google Maps can be explored using 3D controls, as if a flight simulator. Agents can send the flight anywhere and report what they are working on.",
+  "version": "1.0.0",
+  "author": {
+    "name": "John Haugabook",
+    "url": "https://github.com/jhauga"
+  },
+  "keywords": [
+    "copilot-canvas",
+    "flight-simulator",
+    "geography",
+    "google-maps",
+    "interactive-canvas",
+    "session-breaks",
+    "threejs"
+  ],
+  "logo": "assets/preview.png",
+  "extensions": "."
+}