feat(contracts): v0.0.43 — Slice 3.3 origin-escrow template SCAFFOLD (multi-party + dispute) 🎉

Ship Slice 3.3 v0.0.43 — second foundational template del Origin Contract Atelier.
Multi-party escrow + time-locked milestones + dispute-enabled via Pillar 6 Tribunal.

Cambios:
- contracts/origin-escrow/Cargo.toml: ink! 6.0.0-beta.1 + scale codec aligned
- contracts/origin-escrow/lib.rs: full ink! v6 contract source ~500 LOC:
  * 5-state machine canonical (Created → Active → Disputed → Releasing → Completed)
  * Storage canonical: parties (depositor + beneficiary + arbiter + treasury) +
    config (terms_hash + total + fee + windows) + state tracking + milestones mapping
  * 5 events canonical (Deposited, MilestoneCompleted, DisputeRaised,
    DisputeResolved, EscrowCompleted)
  * 12 error variants canonical (InvalidState, UnauthorizedCaller, etc.)
  * Constructor canonical con invariants compile-detect (fee ≤ 5% BM V2 §5.3,
    depositor != beneficiary, terms_hash != zero)
  * 9 read methods canonical (state, parties, amounts, milestones)
  * 5 write methods canonical (deposit, add_milestone, confirm_milestone,
    raise_dispute, resolve_dispute)
  * 4 Resolution variants Tribunal: ReleaseToBeneficiary, RefundToDepositor,
    SplitFifty, Custom (with depositor_bps + beneficiary_bps == 10_000 invariant)
  * 3 unit tests canonical
- contracts/origin-escrow/README.md: use cases + state machine diagram +
  resolution patterns + cross-pillar integration

Inmutables compliance:
- #16 HTS anti-clasista: escrow_fee_bps cap 5% BM V2 §5.3
- #26 Content-Addressed: terms_hash + description_hash BLAKE3 inmutable
- #37 Free perpetua: 9 read methods sin payment
- #41 AGI Cross-Species: AGI puede ser depositor/beneficiary/arbiter

Cross-pillar wire canonical:
- Pillar 6 Tribunal (Mathi): arbiter = Tribunal contract address
- Pillar 2 OMC Marketplace (Marihan): escrow integrado purchases
- Pillar 1 Hosting (Larihana): refundable hosting fees future
- Pillar 4 Origin Chain (Charon): deploy vía pallet-revive Index 11

Use cases canonical:
- Freelance contracts (client + worker + Tribunal)
- OMC marketplace purchases (buyer + seller + Tribunal)
- Institutional partnerships (university + researcher + Tribunal)
- Refundable event tickets (organizer + holder + Tribunal)

Próximo Ship Slice 3.4 v0.0.44: origin-credential-mint contract template
(Ed25519 + BLAKE3 attestation, Sussi Ethos schema integration).

⚓ Path A Slice 3.3 SCAFFOLD shipped. Templates library canonical 2/5 complete.

🤖 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

contracts/origin-escrow/Cargo.toml

@@ -0,0 +1,41 @@
+[package]
+name = "origin-escrow"
+version = "0.1.0"
+edition = "2021"
+authors = [
+    "Charon <charon@originmetaverse.com>",
+    "David Herran <david@dreamhousestudios.com>",
+    "Origin Metaverse community",
+]
+license = "MIT OR Apache-2.0"
+description = "Origin Chain Escrow contract template — multi-party + time-locked + dispute-enabled via Pillar 6 Tribunal integration. Para commerce + freelance + institutional partnerships. Second foundational template del Origin Contract Atelier."
+homepage = "https://originmetaverse.com"
+repository = "https://git.originmetaverse.com/Origin_Metaverse/arkhe-origin-chain"
+keywords = ["smart-contract", "escrow", "ink", "polkavm", "origin-metaverse"]
+categories = ["cryptography::cryptocurrencies", "no-std", "wasm"]
+
+[dependencies]
+ink = { version = "6.0.0-beta.1", default-features = false }
+scale = { package = "parity-scale-codec", version = "3.7", default-features = false, features = ["derive"] }
+scale-info = { version = "2.11", default-features = false, features = ["derive"] }
+
+[lib]
+path = "lib.rs"
+
+[features]
+default = ["std"]
+std = [
+    "ink/std",
+    "scale/std",
+    "scale-info/std",
+]
+ink-as-dependency = []
+e2e-tests = []
+
+[profile.release]
+panic = "abort"
+lto = true
+opt-level = "z"
+overflow-checks = false
+codegen-units = 1
+strip = "symbols"