feat(share): export the share-view codec and link-path helpers (#1419)

* feat(share): export the share-view codec for host servers

Add `@gods-eye-view/core/share/view-codec` (src/share/viewCodec.js) as a
package export with its own boundary group. The codec is pure (no DOM, no
Cesium, no external dependencies), so a host's server can decode a
/share/<code> link, for example to describe the view in link previews.

* feat(share): export the share-link address helpers

Add `@gods-eye-view/core/share/link-path` (src/share/shareLinkPath.js), so a
host's server reads /share/<code> addresses the way the app does.

scripts/package-boundaries.json

@@ -3887,6 +3887,39 @@
     ],
     "external": []
   },
+  "share-view-codec": {
+    "exports": ["./share/view-codec"],
+    "modules": [
+      "src/share/viewCodec.js",
+      "src/share/follow.js",
+      "src/share/wire.js",
+      "src/ui/visualPresets.js",
+      "src/bloom.js",
+      "src/styles/anime.js",
+      "src/styles/noir.js",
+      "src/styles/retro.js",
+      "src/styles/snow.js",
+      "src/styles/surveillance.js",
+      "src/styles/thermal.js",
+      "src/view/index.js",
+      "src/data/layerState.js",
+      "src/data/layerStateTokenReservations.json",
+      "src/data/idSwitches.js",
+      "src/data/detectionPolicy.js",
+      "src/scopeMaskPolicy.js",
+      "src/i18n/index.js",
+      "src/i18n/locale.js",
+      "src/i18n/locales/es.json",
+      "src/i18n/locales/ru.json",
+      "src/i18n/locales/zh-CN.json"
+    ],
+    "external": []
+  },
+  "share-link-path": {
+    "exports": ["./share/link-path"],
+    "modules": ["src/share/shareLinkPath.js"],
+    "external": []
+  },
   "ghostmaps": {
     "exports": ["./layers/ghostmaps"],
     "modules": [