chore(scripts): drop private host names from the demo tooling

The demo migration was named after the host it targets, and its
README, the v1.5 demo seed and a contributing note named the
maintainer's servers, a container id, an app id and two account ids.
The script already takes every host, container and account from its
environment, so the prose now says source and target and lists the
variables instead. It is renamed to migrate-demo-account.sh; the
password guard follows the new name.

scripts/README.md

@@ -37,7 +37,7 @@ typecheck.
 - **`repair-google-health-sleep.ts`**: re-syncs every Google Health connection so nights stored twice before v1.28.18 collapse to one set; dry-run by default, `--run` to execute.
 - **`i18n-key-tool.mjs`**, **`split-description.mjs`**: edit one key across every `messages/*.json` (show, set, drop) and move an over-long card description's tail into its own key; **`measure-description-lengths.mjs`** measures the Settings and Admin description strings against the 120-character guideline.
 - **`audit-column-readers.ts`**: lists write-only schema columns and open `@pending-consumer` markers; a review tool, not a gate.
-- **`migrate-demo-edge01.sh`**: copies the demo account from one instance to a separate demo instance; see its README.
+- **`migrate-demo-account.sh`**: copies the demo account from one instance to a separate demo instance; see its README.
 - **`__tests__/`**: tests for the scripts above.
 
 ## Conventions