Swarm Phase 3a: src/services/wire-types.ts — TypeScript types + JCS canonicalize helper

[Dewinator]

Why

Phase 0/1/2 are landed (SWARM_SPEC, node identity, Ed25519 signature service). Phase 3 starts implementing the wire format defined in docs/SWARM_SPEC.md. This issue is the type-and-canonicalization foundation that every later wire-touching piece reuses.

Background — read this BEFORE starting

• mcp__vector-memory__prime_context with task_description "implement TypeScript wire types and JCS canonicalization for mycelium swarm"
• Read docs/SWARM_SPEC.md §2 (JCS) and §3 (Wire types) carefully — the field tables are the source of truth
• Look at src/services/signature.ts (PR feat(swarm): signature service — Ed25519 sign/verify over JCS (#77) #82) — it already imports a JCS canonicalizer; reuse the same library

What this issue delivers

A new file src/services/wire-types.ts containing:

1. TypeScript interfaces for the four wire record kinds defined in §3:
   • Lesson (§3.1)
   • HubAnchor (§3.2)
   • NodeAdvertisement (§3.3)
   • TrustEdge (§3.4) — local-only, but the type still belongs here
2. A const WIRE_SPEC_VERSION = "1.0" (matches §1)
3. A typed helper canonicalizeForSigning<T extends { signature?: string }>(record: T): Uint8Array that:
   • Strips signature if present
   • Returns the JCS bytes via the same canonicalizer signature.ts uses
4. A typed helper kindOf(record: unknown): "lesson" | "hub_anchor" | "node_advertisement" | "trust_edge" | null — best-effort discriminator using required-field presence

Plus tests in tests/services/wire-types.test.ts:

• One example record per kind that satisfies the interface (compile-time check via satisfies)
• canonicalizeForSigning is deterministic (call twice, byte-equal)
• canonicalizeForSigning strips signature (record with vs. without signature produces same bytes)
• kindOf correctly classifies each example and returns null on garbage

Acceptance criteria

• src/services/wire-types.ts exists and exports the four interfaces, WIRE_SPEC_VERSION, canonicalizeForSigning, kindOf
• tests/services/wire-types.test.ts runs green (at least 6 assertions)
• No new runtime dependency unless signature.ts already pulled it in
• No DB, no HTTP, no file I/O — pure module

Hard constraints

• DO NOT touch the SWARM_SPEC. If the spec is ambiguous, leave a TODO referencing the section and pick the most conservative interpretation.
• DO NOT add a runtime validator here — that's Phase 3b (separate issue).
• DO NOT add HTTP handlers — that's Phase 3c.

Out of scope

• Rejection rules from §5 → Phase 3b
• Endpoints from §4 → Phase 3c+
• Storage schema → Phase 3d

[Dewinator]

Implementiert in 329ce06 (direkt auf main gemerged, kein PR-Review nötig — Reed hat manuell übernommen). Phase 3b/3c/3d (#86/#87/#88) bleiben offen für den nächsten Loop-Run.