Add chargepoint domain skill: Datadome blocks password login, use coulomb_sess cookie

domain-skills/chargepoint/auth.md

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+# ChargePoint — session auth (driver.chargepoint.com)
+
+## Datadome blocks programmatic password login
+
+ChargePoint fronts its login API with Datadome bot protection. Server-side
+password logins (e.g. from the Home Assistant `chargepoint` custom integration,
+or any script POSTing credentials) get blocked with a bot challenge even when
+the credentials are correct. Don't retry the password path — use a session
+token from a real browser instead.
+
+## The session token is the `coulomb_sess` cookie
+
+- Domain: `.chargepoint.com` (shared across driver.chargepoint.com and na.chargepoint.com)
+- Name: `coulomb_sess` (~43-char opaque value)
+- Present whenever the user is logged in at https://driver.chargepoint.com
+- Related cookies you'll see alongside it: `auth-session`, `ci_ui_session`,
+  `datadome` — `coulomb_sess` is the one API clients (python-chargepoint,
+  ha-chargepoint) accept as a session token.
+
+Grab it from the user's logged-in browser without navigating anywhere:
+
+```python
+cookies = cdp("Storage.getCookies")["cookies"]
+tok = next(c["value"] for c in cookies
+           if c["name"] == "coulomb_sess" and "chargepoint" in c["domain"])
+```
+
+If no `coulomb_sess` cookie exists, the user isn't logged in — stop and ask
+them to log in at driver.chargepoint.com first (don't type credentials).
+
+## Trap
+
+The HA chargepoint integration's reauth dialog offers both a password field
+and a token field. The password path fails through HA's server (Datadome
+again); paste the `coulomb_sess` value into the token field instead —
+succeeds immediately.