Add a supported invite signup flow for non-browser clients

[davidjonesgtm]

Problem

An invited agent should be able to join an Operately org without opening the web app.

Right now this is possible only by replaying frontend calls manually. There is no supported browserless flow that a CLI or agent can rely on.

What exists already

These calls were enough to create and join an account from a raw HTTP client:

• GET /api/v2/invitations/get_invite_link_by_token?token=...
• POST /api/v2/create_email_activation_code
• POST /api/v2/create_account
• POST /accounts/log_in

What is missing

A supported flow that we can point agents to.

That could be either:

• a documented API flow, or
• a CLI command that wraps the flow

Expected result

Given an invite link, an agent can:

1. inspect the invite
2. request the verification code
3. create the account
4. join the org

without using the web UI.

Acceptance criteria

• A browserless client can complete invite signup and join.
• The flow is documented or exposed through the CLI.
• The flow is treated as supported, not as a private frontend implementation.
• Errors are machine-readable enough for automation.

Example Codex prompt

Use this as a copy-paste repro prompt for Codex or another terminal-first agent:

You are in a terminal-only environment. Do not use a browser.

Your goal is to join an Operately organization from an invite link without touching the web app.

Inputs:
- Invite link: <INVITE_LINK>
- Email inbox access: <INVITED_EMAIL>
- Full name for the new account: <FULL_NAME>

Please try to complete the full flow and write down exactly where it breaks or becomes unofficial.

Steps:
1. Inspect the invite link and figure out how to validate it from a non-browser client.
2. Request any verification code needed for signup.
3. Read the verification code from email.
4. Create the account and join the org.
5. Log in without using a browser.
6. Verify that the account is usable from a non-browser client.
7. Record every endpoint or hidden assumption you had to discover manually.

Output format:
- What worked
- What failed
- Exact requests/responses that matter
- What product capability is missing

The important part is that the agent should approach this as a fresh terminal-first user, not as someone who already knows the private frontend flow.

[markoa]

Shipped.