TW-4843 Harden CLI retry, dashboard auth, and updater flows

[qasim-nylas]

Summary

This PR hardens several Nylas CLI correctness and reliability paths found during review of the current branch.

It fixes:

• replay of JSON request bodies on retried write requests
• dashboard multi-org login/session selection consistency
• dashboard POST response decoding for nested data payloads
• Windows self-update staging and rollback safety for a running executable

Jira: TW-4843
Epic: TW-4638

Changes

• add safe request cloning/body replay for retry attempts in the Nylas HTTP client
• add regression coverage proving retried update requests resend the original JSON payload
• switch dashboard org selection to the real server-side session org during login/SSO
• stop double-unwrapping dashboard POST responses
• stage Windows updates through a deferred replacement script instead of direct in-process replacement
• preserve the backup binary until Windows replacement succeeds, and restore it on failure
• add updater regression tests for staging, rollback behavior, and batch path escaping

Validation

• targeted regression tests for retry replay, dashboard org switching, nested response decoding, and Windows updater staging/rollback
• make ci-full passed 4 consecutive times

Residual Risk / Follow-up

• the Windows updater path is unit-tested but still needs a real Windows smoke test
• dashboard org switching is covered at the helper/service level; an end-to-end CLI smoke test would be additional hardening, not a blocker

Notes

This PR is intentionally focused on correctness and production safety rather than refactoring or behavior expansion.

[AaronDDM]

LGTM 👍