fix(dev): make worktree setup run on Windows (#2431)

`worktree.setup` ran two POSIX-only command strings, but lifecycle commands
go through PowerShell on Windows, so worktree creation failed at:

    PASEO_DEV_MANAGED_HOME=1 PASEO_DEV_SEED_HOME=... ./scripts/dev-home.sh
    -> PASEO_DEV_MANAGED_HOME=1 : The term ... is not recognized

PowerShell has no `VAR=value cmd` prefix syntax. The `cp` entry was broken the
same way: `$PASEO_SOURCE_CHECKOUT_PATH` is an undefined *PowerShell* variable,
not an env var, so it expanded to empty and the copy resolved to
`/packages/server/.env`.

Neither entry can be expressed portably in a single shell string, and `bash` is
not guaranteed on Windows, so move both steps into a Node script that reads its
inputs from `process.env` — matching the existing
`node ./scripts/seed-ios-native-cache.mjs` entry. One code path, no platform
branching.

`scripts/dev-home.sh` is unchanged and still sourced by the bash service
scripts; only the setup-time seeding is ported.

One behavior change: a missing `packages/server/.env` in the source checkout is
now skipped with a log instead of aborting setup. It is untracked local config,
and the old `cp` hard-failed worktree creation for anyone without one.

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

paseo.json

@@ -3,10 +3,9 @@
     "setup": [
       "npm ci",
       "node ./scripts/seed-ios-native-cache.mjs",
-      "PASEO_DEV_MANAGED_HOME=1 PASEO_DEV_SEED_HOME=\"$PASEO_SOURCE_CHECKOUT_PATH/.dev/paseo-home\" PASEO_HOME=\"$PWD/.dev/paseo-home\" ./scripts/dev-home.sh",
+      "node ./scripts/seed-worktree-dev-state.mjs",
       "npm run build:server",
-      "npm run build --workspace=@getpaseo/expo-two-way-audio",
-      "cp \"$PASEO_SOURCE_CHECKOUT_PATH/packages/server/.env\" \"$PWD/packages/server/.env\""
+      "npm run build --workspace=@getpaseo/expo-two-way-audio"
     ]
   },
   "scripts": {