docs: add same-port Claude Code profile launcher example

[davetha]

Summary

• add a small shell example for launching Claude Code against the same Meridian port while selecting personal or company via ANTHROPIC_CUSTOM_HEADERS
• keep the example intentionally simple so users can adapt it to local shell aliases or wrappers

Use Case

I have both a personal and a company Claude account/plan, and I want to reach one Meridian instance from several systems over my local network or a private Tailscale tunnel instead of installing Meridian and repeating claude auth on every machine.

This example shows the last mile for that setup: keep one Meridian port, then launch Claude Code with the right profile header so the client feels separated in a similar way to having per-system claude auth, while still centralizing control.

Dependency

Draft because this stacks on top of:

• feat: add profile-based routing foundation #161

GitHub cannot express the exact stacked base across forks, so this draft PR includes earlier profile-routing work until #161 merges.

Verification

• bash -n examples/claude-code-profile.sh

[davetha]

Superseded by #165