feat(canvas): strip demo data, EA2 is the only source

- Remove src/data/synthetic.ts + its test (AR refund, HCM onboarding,
  GL close, Service Ops blueprints were hand-modelled fakes).
- Remove DataMode='snapshot'; the store now boots straight into live
  EA2 with no fallback. EA2 errors surface as toasts, not fake data.
- Topbar / Settings / CommandBar wording: 'SNAPSHOT'/'LIVE' becomes
  the unambiguous 'EA2' badge. No more user-facing mode switch.
- package.json name flowmaster-mission-control-demo → flowmaster-canvas.
- README rewritten — no longer calls the product a demo.
- store.test: drop the two tests that relied on synthetic scenarios
  always being present; add one asserting an EA2-empty response leaves
  the store cleanly empty (no error-stuck state).

All 23 vitest tests pass. tsc + vite build green. Bundle dropped
from ~238 kB gz → ~234 kB gz.

package.json

@@ -1,5 +1,5 @@
 {
-  "name": "flowmaster-mission-control-demo",
+  "name": "flowmaster-canvas",
   "private": true,
   "version": "1.0.0",
   "type": "module",