fix(peer): parse envelopes by attribute name (hop-chain)

[androidand]

Claude Code now adds a hop-chain attribute to relayed messages. parseEnvelope accepted exactly three attributes, so those replies arrived as an unknown sender: no reply address, and lead verification impossible for a Claude Code lead.

Attributes are now read by name (first wins, unknown ignored, hopChain exposed); from is required, otherwise raw text. Anchors kept so a forged envelope in the body stays inert. 4 new tests red before the fix; peer suite 194 pass; fork:verify OK.

🤖 Generated with Claude Code

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