feat(warp-core): TTD domain logic — provenance storage + causal cone walk

CHANGELOG.md

@@ -5,6 +5,45 @@
 
 ## Unreleased
 
+### feat(warp-core): Wire up TTD domain logic from ttd-spec branch
+
+- **Exported** `compute_tick_commit_hash_v2`, `compute_op_emission_index_digest`,
+  and `OpEmissionEntry` from `warp-core` public API (previously `dead_code`).
+- **Wired** `LocalProvenanceStore::append_with_writes()` to actually store
+  atom writes instead of discarding them.
+- **Added** `LocalProvenanceStore::atom_writes(w, tick)` — query atom writes
+  for a specific tick (TTD "Show Me Why" provenance).
+- **Added** `LocalProvenanceStore::atom_history(w, atom)` — causal cone walk
+  using `out_slots` (Paper III `Out(μ)`) to filter ticks that wrote to
+  the atom, with early termination at creation. O(history) scan, no reverse index.
+- **Fixed** `LocalProvenanceStore::fork()` to copy `atom_writes` alongside
+  patches, expected hashes, and outputs.
+- **Added** 12 tests covering atom write storage, queries, filtering, fork,
+  causal-cone walk, skip behavior, early termination, within-tick ordering,
+  and `SlotId::Node(atom)` provenance path.
+
+### test(echo-dind-harness): Golden-vector coverage for TTD digest surface
+
+- **Added** `digest_golden_vectors.rs` — DIND-level golden-hash tests that
+  exercise `compute_emissions_digest`, `compute_op_emission_index_digest`,
+  and `compute_tick_commit_hash_v2` through warp-core's crate-root re-exports.
+- **Pinned** 3 golden vectors: individual emission/op-emission-index digests
+  plus a full hash chain (emissions → op-index → tick-commit). Any wire format
+  drift in the public digest surface is now caught outside module-local tests.
+
+### fix(warp-core): Preserve within-tick write order in atom_history
+
+- **Fixed** `atom_history()` within-tick write ordering: the backward tick
+  walk collected per-tick writes in forward order, so the final `reverse()`
+  flipped within-tick execution sequence. Iterate `tick_writes.iter().rev()`
+  so the global reverse restores original order.
+- **Fixed** creation truncation: if a single tick had `[create, mutate]` for
+  the same atom, forward iteration hit `is_create()` first and returned early,
+  losing the subsequent mutation.
+- **Updated** `fork()` rustdoc to mention `atom_writes` in the copied fields.
+- **Documented** `append_with_writes()` invariant: atom writes must reference
+  atoms declared in `patch.out_slots` for `atom_history()` visibility.
+
 ### fix: Ban-globals regex for macro patterns
 
 - **Fixed** `scripts/ban-globals.sh`: the `\bthread_local!\b` and

crates/echo-dind-harness/tests/digest_golden_vectors.rs

@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: Apache-2.0
+// © James Ross Ω FLYING•ROBOTS <https://github.com/flyingrobots>
+#![allow(clippy::unwrap_used)]
+//! Golden-vector tests for the TTD digest public API surface.
+//!
+//! These tests exercise `compute_emissions_digest`, `compute_op_emission_index_digest`,
+//! and `compute_tick_commit_hash_v2` through warp-core's **crate-root re-exports** —
+//! not via internal module paths. If a re-export is removed or a wire format changes,
+//! these tests catch it.
+//!
+//! Each function is pinned to a known-good hash. The full chain is then exercised:
+//! emissions → op-emission-index → tick-commit, so drift in any layer is detected.
+
+use warp_core::materialization::{make_channel_id, FinalizedChannel};
+use warp_core::{
+    compute_emissions_digest, compute_op_emission_index_digest, compute_tick_commit_hash_v2,
+    OpEmissionEntry, WorldlineId,
+};
+
+// ─── Test vectors ────────────────────────────────────────────────────────────
+
+/// Creates a 32-byte hash where every byte position is distinguishable.
+/// This catches serializer bugs that drop, reorder, or endian-flip tail bytes
+/// (a uniform [n, 0, 0, ...] fixture would mask such issues).
+fn make_hash(seed: u8) -> [u8; 32] {
+    #[expect(clippy::cast_possible_truncation, reason = "i ∈ 0..32, fits in u8")]
+    core::array::from_fn(|i| seed.wrapping_add((i as u8).wrapping_mul(17)))
+}
+
+// ─── compute_emissions_digest ────────────────────────────────────────────────
+
+#[test]
+fn emissions_digest_golden_vector() {
+    let ch_a = make_channel_id("alpha");
+    let ch_b = make_channel_id("beta");
+
+    let channels = vec![
+        FinalizedChannel {
+            channel: ch_a,
+            data: vec![1, 2, 3],
+        },
+        FinalizedChannel {
+            channel: ch_b,
+            data: vec![4, 5],
+        },
+    ];
+
+    let digest = compute_emissions_digest(&channels);
+    let hex = hex::encode(digest);
+
+    // Pinned golden value. If this changes, the emissions wire format changed.
+    assert_eq!(
+        hex, "9cd163d40fd2b8b089c5bed80c328ffc5695926cdbe2aaf1a99c83adf0bbe2ea",
+        "emissions_digest golden vector mismatch — wire format may have changed!\nactual: {hex}"
+    );
+}
+
+// ─── compute_op_emission_index_digest ────────────────────────────────────────
+
+#[test]
+fn op_emission_index_digest_golden_vector() {
+    let ch_a = make_channel_id("alpha");
+    let ch_b = make_channel_id("beta");
+
+    let entries = vec![
+        OpEmissionEntry {
+            op_id: make_hash(0xAA),
+            channels: vec![ch_a, ch_b],
+        },
+        OpEmissionEntry {
+            op_id: make_hash(0xBB),
+            channels: vec![ch_a],
+        },
+    ];
+
+    let digest = compute_op_emission_index_digest(&entries);
+    let hex = hex::encode(digest);
+
+    // Pinned golden value. If this changes, the op-emission-index wire format changed.
+    assert_eq!(
+        hex, "cbb1f5f73d0b5da137b0bde7b7d242fb44b8b6d0f5d4f8391105b6c36aa7a974",
+        "op_emission_index_digest golden vector mismatch — wire format may have changed!\nactual: {hex}"
+    );
+}
+
+// ─── compute_tick_commit_hash_v2 (full chain) ────────────────────────────────
+
+#[test]
+fn tick_commit_hash_v2_full_chain_golden_vector() {
+    // Build the hash chain: emissions → op-emission-index → tick-commit.
+    // This exercises the full TTD provenance digest surface end-to-end.
+
+    let ch_a = make_channel_id("alpha");
+    let ch_b = make_channel_id("beta");
+
+    // Step 1: Compute emissions digest
+    let channels = vec![
+        FinalizedChannel {
+            channel: ch_a,
+            data: vec![1, 2, 3],
+        },
+        FinalizedChannel {
+            channel: ch_b,
+            data: vec![4, 5],
+        },
+    ];
+    let emissions_digest = compute_emissions_digest(&channels);
+
+    // Step 2: Compute op-emission-index digest
+    let entries = vec![OpEmissionEntry {
+        op_id: make_hash(0xAA),
+        channels: vec![ch_a, ch_b],
+    }];
+    let op_emission_index_digest = compute_op_emission_index_digest(&entries);
+
+    // Step 3: Compute tick commit hash using the above digests
+    let schema_hash = make_hash(0xAB);
+    let worldline_id = WorldlineId(make_hash(0xCD));
+    let tick = 42u64;
+    let parent = make_hash(0x11);
+    let patch_digest = make_hash(0x22);
+    let state_root = make_hash(0x33);
+
+    let commit_hash = compute_tick_commit_hash_v2(
+        &schema_hash,
+        &worldline_id,
+        tick,
+        &[parent],
+        &patch_digest,
+        Some(&state_root),
+        &emissions_digest,
+        Some(&op_emission_index_digest),
+    );
+    let hex = hex::encode(commit_hash);
+
+    // Pinned golden value for the full chain. If this changes, any layer's
+    // wire format may have changed — check individual tests above to isolate.
+    assert_eq!(
+        hex, "8a769a8d8dd847be4ff546f1214a44d49446f05a0a10450b5d0ec21bd68613e9",
+        "tick_commit_hash_v2 full-chain golden vector mismatch!\nactual: {hex}"
+    );
+}

crates/warp-core/src/lib.rs

@@ -190,7 +190,8 @@ pub use serializable::{
     SerializableReceipt, SerializableReceiptEntry, SerializableSnapshot, SerializableTick,
 };
 pub use snapshot::{
-    compute_commit_hash_v2, compute_emissions_digest, compute_state_root_for_warp_store, Snapshot,
+    compute_commit_hash_v2, compute_emissions_digest, compute_op_emission_index_digest,
+    compute_state_root_for_warp_store, compute_tick_commit_hash_v2, OpEmissionEntry, Snapshot,
 };
 pub use telemetry::{NullTelemetrySink, TelemetrySink};
 pub use tick_delta::{DeltaStats, OpOrigin, ScopedDelta, TickDelta};