fix(env): expand ~ relative to the home directory in resolvePath

[shani-singh1]

Summary

resolvePath("~/workspace") returns /workspace (the home directory is dropped) instead of <home>/workspace. The ~ expansion in env.ts is broken on every platform, so pointing EGO_BROWSER_AGENT_WORKSPACE at a ~-relative path resolves the agent workspace (and therefore learnings, .env loading, and agent_helpers.js) to the wrong directory.

Root cause

package/ego-browser/src/env.ts:

export function resolvePath(path) {
  if (path.startsWith("~")) {
    return resolve(process.env.HOME || process.env.USERPROFILE || ".", path.slice(1));
  }
  return resolve(path);
}

For "~/workspace", path.slice(1) is "/workspace". path.resolve(home, "/workspace") treats /workspace as an absolute path segment, so it returns /workspace and discards home entirely. This is path.resolve's documented right-to-left absolute-segment behavior.

Verified against the built runtime (HOME set to /home/ego-test):

resolvePath("~/workspace") -> /workspace        (expected /home/ego-test/workspace)

~ survives literally when EGO_BROWSER_AGENT_WORKSPACE is set in a .env file (loadEnvFile does not shell-expand), which is exactly what resolvePath exists to handle.

Fix

Join the remainder to the home directory instead of resolving it as a fresh absolute path, so ~ stays home-relative:

const home = process.env.HOME || process.env.USERPROFILE || ".";
return resolve(join(home, path.slice(1)));

join keeps the leading slash from path.slice(1) relative ("~" -> home, "~/ws" -> home/ws); the outer resolve normalizes.

Verification

• New env.test.mjs: resolvePath("~/workspace"), "~", and "~/a/b" now resolve under the home directory; a non-tilde path still resolves to an absolute path. Fails before this change (~/workspace -> /workspace), passes after. Cross-platform (uses the current OS home/join).
• Full npm test, tsc --noEmit, and prettier --check are clean.

Impact

• Public helper API or behavior (resolvePath / EGO_BROWSER_AGENT_WORKSPACE with a ~ path)
• No externally visible impact for absolute or non-tilde workspace paths