Document DigiKey and Mouser search

[seveibar]

Summary

• document tsci search --digikey and tsci search --mouser in the CLI reference and default workflow
• show how to combine both suppliers and consume unified --json output
• explain cached stock semantics and supplier-specific part-number fields
• clarify that unfiltered search defaults to JLCPCB and that DigiKey/Mouser are discovery sources, not direct tsci import sources

Why

The CLI supplier-search integrations need matching agent guidance so generated workflows choose the intended source and do not incorrectly assume distributor results can be imported directly.

Depends on tscircuit/cli#4116 and tscircuit/cli#4119.

Validation

• git diff --check
• manually checked every DigiKey/Mouser command and JSON field against the CLI implementation

[tscircuitbot]

---

Thank you for your contribution! 🎉

PR Rating: ⭐
Impact: Tiny

Track your contributions and see the leaderboard at: tscircuit Contribution Tracker

---