feat(examples): add multisig example to Rust and all bindings

[shaibuafeez]

Summary

• Add multisig example to Rust and all 4 bindings (Go, Kotlin, Python, Swift)
• Derives 3 keypairs from a mnemonic, creates a multisig committee (threshold=2), funds via faucet, signs with 2-of-3 keys, aggregates, and executes
• Follows the reference TS example: https://github.com/Thoralf-M/iota-examples/blob/main/wallet/transactions/multisig.ts

Test plan

• Rust: cargo build --example multisig — compiles clean
• Rust: cargo clippy --example multisig — zero warnings
• Go: go vet + go build — clean
• Kotlin: gradlew build + gradlew example -Pexample=Multisig — compiles and runs
• Python: FFI imports verified, mnemonic derivation produces correct address
• Swift: swift build — compiles and links clean
• Full end-to-end: requires localnet (iota start --force-regenesis)

[Thoralf-M]

CI is failing

Running Go example "multisig"
2026/02/27 07:58:22 Multisig address: 0x2e8ebd8d59ec30a44930b72620bebf235fb6d90d205ec599808657a44a56c478
panic: interface conversion: error is nil, not *iota_sdk.SdkFfiError

goroutine 1 [running]:
main.main()
	/home/runner/work/iota-rust-sdk/iota-rust-sdk/bindings/go/examples/multisig/main.go:83 +0xc9d
exit status 2

and for Kotlin format run make kotlin-examples-format

[Thoralf-M]

Still need to format kotlin make kotlin-examples-format

[Thoralf-M]

Thanks!

[shaibuafeez]

Thanks!

anytime 🫡

[thibault-martinez]

We have merged C# since you opened the PR, would you mind adding an example for it? Otherwise we will do it.

[shaibuafeez]

We have merged C# since you opened the PR, would you mind adding an example for it? Otherwise we will do it.

I should help add for C# too?

sure.

[shaibuafeez]

Done

[thibault-martinez]

Thank you :)

[shaibuafeez]

Thank you :)

Any time 🫡

[Alex6323]

Any reason why we should not have this in the corresponding bindings examples as well? I guess users who are looking for examples for their particular langue don't necessarily also check the Rust example?