Add process-local `WGPeerConfig` entries and make
`WGInterfaceConfig` own a unique peer tuple for listener and dial
provisioning.
Deats,
- carry peer public keys, allowed CIDRs and optional endpoints
- redact per-peer preshared keys while blocking wire encoding
- validate peer routes, endpoint ports and keepalive intervals
- reject duplicate peers before future kernel mutation
- support multi-peer listeners without overloading tunnel identity
Prompt-IO: ai/prompt-io/opencode/20260826T001442Z_dcdf4d82_prompt_io.md
(this patch was generated in some part by `opencode` using `gpt-5.6-sol` (`openai`))