feat(governance): v0.0.28 origin-chain-governance pallet scaffold (Phase 5.1 Foundation Treasury CHN-4)

Phase 5.1 GOVERNANCE pallet scaffold canonical. Reemplaza placeholder
GovernanceConfig stub en existing origin-chain-governance crate con real FRAME
pallet. AI-Driven Human-Guarded canonical CHN-4 — 5 AI advisor agents ADVISE
only, humans-only vote canonical non-negotiable.

## Pallet surface canonical

- Pallet<T> + Config trait + RuntimeEvent
- Proposal struct (11 fields content-addressed via BLAKE2-256)
- ProposalStatus enum (Voting + Approved + Rejected + Withdrawn)
- Proposals<StorageMap<ProposalId, Proposal>> per-proposal O(1)
- Votes<StorageDoubleMap<ProposalId, AccountId, VoteStance>> double-vote prevention
- Events ProposalSubmitted + VoteCast + ProposalFinalized
- Errors 8 variants (ProposalNotFound + AlreadyVoted + VotingPeriodClosed/Open + StakeInsufficient + ProposalAlreadyFinalized + AdvisorMayNotVote + ProposalIdCollision)
- Scaffold dispatchables submit_proposal + cast_vote + finalize_proposal
- Helper derive_proposal_id via BLAKE2-256 hash (Inmutable #16 byte-determinism)
- sp_api::decl_runtime_apis! GovernanceApi declaration (query_proposal + query_vote)

## Types canonical updated

- origin-chain-types/src/governance.rs: added scale derives a ProposalId + VoteStance + Vote (Encode + Decode + DecodeWithMemTracking + MaxEncodedLen + TypeInfo) para FRAME-compatibility canonical

## Files

- EDIT: crates/origin-chain-governance/Cargo.toml (stub → FRAME pallet deps canonical)
- REPLACE: crates/origin-chain-governance/src/lib.rs (placeholder → ~360 LOC scaffold)
- EDIT: crates/origin-chain-types/src/governance.rs (scale derives canonical)
- EDIT: CHANGELOG.md (v0.0.28 entry)

## Verification

- cargo test -p origin-chain-governance — 5 tests verde, 0 failures
  (pallet_compiles + derive_proposal_id deterministic + different + status variants + re-export)

🏛️ Phase 5.1 scaffold canonical. Wire pattern v0.0.29 next.

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

crates/origin-chain-governance/Cargo.toml

@@ -7,7 +7,50 @@ license.workspace = true
 authors.workspace = true
 repository.workspace = true
 homepage.workspace = true
-description = "Foundation governance on-chain: Pallet Collective + Pallet Democracy + 5 AI advisor agents, humans-only vote canonical per CHN-4. STUB v0.0.1 — implementation lands Phase 5 of Charon roadmap."
+description = "Foundation governance on-chain canonical: Proposal + Vote + Tally per CHN-4 AI-Driven Human-Guarded. Phase 5.1 v0.0.28 scaffold — humans-only vote enforced canonical, 5 AI advisor agents advise-only canonical."
 
 [dependencies]
-origin-chain-types.workspace = true
+# Origin Chain canonical types (ProposalId + VoteStance + Vote source-of-truth)
+origin-chain-types = { workspace = true }
+
+# FRAME canonical pallet macro + storage + dispatch + events + errors
+frame-support = { workspace = true }
+frame-system = { workspace = true }
+
+# Runtime API canonical (v0.0.31 — GovernanceApi.query_proposal read-only RPC)
+sp-api = { workspace = true }
+
+# Substrate primitives canonical (BLAKE2 hashing canonical para derive_proposal_id)
+sp-core = { workspace = true }
+sp-runtime = { workspace = true }
+
+# SCALE codec canonical
+parity-scale-codec = { workspace = true }
+scale-info = { workspace = true }
+
+[dev-dependencies]
+# Mock runtime canonical para integration tests v0.0.30 — Pattern v0.0.26 mirror.
+sp-core = { workspace = true, default-features = true }
+sp-io = { workspace = true, default-features = true }
+sp-runtime = { workspace = true, default-features = true }
+
+[features]
+default = ["std"]
+std = [
+    "origin-chain-types/std",
+    "frame-support/std",
+    "frame-system/std",
+    "sp-api/std",
+    "sp-core/std",
+    "sp-runtime/std",
+    "parity-scale-codec/std",
+    "scale-info/std",
+]
+runtime-benchmarks = [
+    "frame-support/runtime-benchmarks",
+    "frame-system/runtime-benchmarks",
+]
+try-runtime = [
+    "frame-support/try-runtime",
+    "frame-system/try-runtime",
+]