Initial StartOS package for Station Master (v0.5.1)

Built from source via a git submodule pinned to a tag, not a published image
— the Dockerfile, main.ts, and manifest should never need to change for an
ordinary version bump, only the submodule pin (see UPDATING.md). One volume,
one interface serving the browser client + lobby/intent API + SSE stream
from a single origin, no dependencies. The server-wide join secret (D14) is
seeded on install, exposed via the Get Join Secret action, and blocks start
behind a critical task until retrieved — the same first-set/rotation pattern
as actual-budget-startos's admin password.

Verified on phoenix.local: installs, the critical task correctly blocks an
ordinary start, force-starting confirms the daemon binds its port and serves
the client, and store.json correctly holds the install-seeded join secret.
Not verified: the Get Join Secret action's execution end-to-end — start-cli's
`package action run` fails with a client-side deserialization error that
reproduces identically against actual-budget's already-shipped equivalent
action, so this looks like a start-cli issue rather than a defect here.

icon.svg is still the scaffold's hello-world placeholder — no real Station
Master icon exists yet to ship in its place.

package.json

@@ -0,0 +1,26 @@
+{
+  "name": "station-master-startos",
+  "scripts": {
+    "build": "rm -rf ./javascript && ncc build startos/index.ts -o ./javascript",
+    "prettier": "prettier --write startos",
+    "check": "tsc --noEmit"
+  },
+  "dependencies": {
+    "@start9labs/start-sdk": "2.0.9"
+  },
+  "overrides": {
+    "@start9labs/start-sdk": "$@start9labs/start-sdk"
+  },
+  "devDependencies": {
+    "@types/node": "^22.19.0",
+    "@vercel/ncc": "^0.38.4",
+    "prettier": "^3.6.2",
+    "typescript": "^6.0.3"
+  },
+  "prettier": {
+    "trailingComma": "all",
+    "tabWidth": 2,
+    "semi": false,
+    "singleQuote": true
+  }
+}