feat: support multiple tokens in webhix forward

[GaIsBAX]

Currently webhix forward only accepts a single token, requiring a separate
process per endpoint:

webhix forward abc123 --to localhost:3000
webhix forward def456 --to localhost:3001

Proposed: support multiple tokens in one command:

webhix forward abc123 def456 --to localhost:3000

Considerations:

• If one token's stream fails, others should continue independently
• Router approach (EdziFuri) — independent retry loops per token
• v0.2+ improvement, not blocking MVP