docs(audit): delta brief + diff bundle for Accretion follow-up

Prepares the consolidated state at audit-pending-v1 for Accretion's
delta-audit review. Local-only artifacts; not published, not pushed.

Deliverables under docs/audit/:
- DELTA_BRIEF.md: structured summary by phase (P0-P5), audit asks per phase,
  byte-identity claims vs upstream lazorkit-protocol, slot-share strategy
  context, contact + reproducibility info
- program-src.diff: full unified diff of program/ between
  audit-baseline-2026-02-accretion (d1eaaeb, the prior audited state)
  and audit-pending-v1 (9c97fe2, the new state)
- program-src.diff.stat: per-file changed-line summary
- upstream-parity.txt: byte-identity report — 13/19 changed files
  byte-identical with already-audited lazorkit-protocol; 6 differ only
  for fee-strip / cosmetic reasons (URLs, layout)

Local git tags created (not pushed):
- audit-baseline-2026-02-accretion → d1eaaeb (prior audit baseline)
- audit-pending-v1 → 9c97fe2 (current consolidated state)

Audit ask is explicit per phase:
- P1 action enforcement engine: confirm no new vulnerabilities
- P5 auth/processor port: confirm Accretion's prior review of byte-identical
  upstream files extends to program-v2
- Slot-share compatibility: confirm state account layouts forward-compatible
  for binary swap at LazorjRF… mainnet slot

Per user direction, NOT publishing or pushing yet — awaiting explicit
permission for those operational steps.

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

Author: onspeedhp

docs/audit/DELTA_BRIEF.md

@@ -0,0 +1,255 @@
+# Accretion Audit Delta Brief — `program-v2` `audit-baseline-2026-02-accretion` → `audit-pending-v1`
+
+**Repository:** `lazor-kit/program-v2`
+**Previous audit:** Accretion Labs, Solana Foundation, February 2026, A26SFR1
+([audits/2026-accretion-solana-foundation-lazorkit-audit-A26SFR1.pdf](../../audits/2026-accretion-solana-foundation-lazorkit-audit-A26SFR1.pdf))
+**Previous baseline tag:** `audit-baseline-2026-02-accretion` → commit `d1eaaeb` (Merge PR #49 fix/audit-hardening, 17/17 findings resolved)
+**Delta tag:** `audit-pending-v1` → commit `9c97fe2`
+**Delta scope:** 21 files in `program/`, +4168 / −444 lines
+
+This delta brief is for an **Accretion follow-up engagement** to confirm the
+changes between the two tags introduce no new vulnerabilities versus the prior
+audited state. Most of the new code is **byte-identical with the
+already-audited `lazorkit-protocol` repo** (commercial sibling under the same
+audit engagement); this is documented per-file in
+[upstream-parity.txt](./upstream-parity.txt).
+
+---
+
+## Strategic context (deploy plan)
+
+`program-v2` ships at the **same mainnet program ID** as `lazorkit-protocol`
+(`LazorjRFNavitUaBu5m3WaNPjU1maipvSW2rZfAFAKi`). The foundation contract
+period uses the `program-v2` (no-fee) build at that slot; afterwards, the
+upgrade authority swaps the binary at the same slot to the `lazorkit-protocol`
+(commercial, with-fee) build.
+
+**Implication for audit scope:** binary-swap compatibility requires that
+program-v2 and lazorkit-protocol share identical:
+- Account layouts (Wallet, Authority, Session, DeferredExec — verified
+  byte-identical via `state/*.rs` ↔ upstream)
+- Instruction encoding (discriminators 0–9, account orderings — kept aligned
+  via the IDL sync in P5.4)
+- Auth verification logic (auth/secp256r1/* — byte-identical with upstream
+  after P5.1)
+
+Audit confirmation of this delta therefore also benefits the slot-share
+strategy: any wallet/authority/session created on either binary remains
+verifiable by the other after swap.
+
+---
+
+## Delta by phase
+
+The 23 commits between the two tags group into 5 phases:
+
+### P0 — Cherry-pick guardrails (zero-audit, mechanical)
+
+Tooling-only. Adds `scripts/strip-fee.sh`, `scripts/check-no-fee.sh`,
+`scripts/fee-paths.txt`, and `.github/workflows/check-no-fee.yml` to enforce
+that fee/admin/FeeRecord surface from `lazorkit-protocol` cannot leak into
+`program-v2` during cherry-picks. **No `program/` source changed.**
+
+### P1 — Action types port + execute enforcement (delta-audit)
+
+**Most security-relevant section of the delta.** New on-chain feature.
+
+Files touched:
+- `program/src/state/action.rs` (NEW, 697 lines) — byte-identical with
+  upstream `lazorkit-protocol/program/src/state/action.rs` (already audited).
+  Defines 8 action types + parser + validator.
+- `program/src/state/session.rs` — minor (+23 lines) — adds
+  `SESSION_HEADER_SIZE` const and `actions_slice()` helper. Byte-identical
+  with upstream.
+- `program/src/state/mod.rs` — adds `pub mod action;`.
+- `program/src/processor/create_session.rs` — adopts variable-size session PDA
+  for optional actions buffer + validation at creation. Byte-identical with
+  upstream.
+- `program/src/processor/execute_actions.rs` (NEW, 1644 lines) —
+  byte-identical with upstream `lazorkit-protocol/program/src/processor/execute/actions.rs`.
+  Pre-CPI program whitelist/blacklist + token snapshots; post-CPI delta
+  computation, SOL/token cap enforcement, recurring window resets, vault
+  invariant defenses against System::Assign / SetAuthority escapes.
+- `program/src/processor/execute.rs` — wires pre/post action evaluation
+  around the CPI loop, adds the L5 anti-CPI guard for sessions, gross SOL
+  outflow tracking. Differs from upstream `processor/execute/immediate.rs`
+  by **1 import-path line** (`processor::execute_actions::` vs
+  `processor::execute::actions::`) due to flat vs nested processor layout.
+- `program/src/error.rs` — adds 13 error variants (3020–3032) for action
+  validation, enforcement, and vault invariant defense.
+
+**Audit ask (P1):** Confirm action enforcement engine + execute integration
+introduce no new vulnerabilities vs. the audited upstream version.
+
+### P2 — Dual-cluster + security_txt (zero-audit, mechanical)
+
+- `program/src/lib.rs` — embeds `security_txt!` with program-v2-specific URLs
+  (only difference vs upstream is the URL strings — see `upstream-parity.txt`)
+- `assertions/src/lib.rs`, `assertions/Cargo.toml`, `program/Cargo.toml` —
+  Pattern D feature flags: `--features mainnet` embeds `LazorjRF…` (slot
+  shared with upstream); `--features devnet` embeds `FLb7…`; no feature →
+  `compile_error!` (prevents accidental cross-cluster deploy)
+
+No on-chain logic change. Build-time configuration only.
+
+### P3 — SDK consolidation (no audit)
+
+Off-chain only. `program-v2/sdk/solita-client/` deleted; `program-v2/tests-sdk/`
+migrated to `@lazorkit/sdk-legacy` from npm (the same SDK
+`lazorkit-protocol` ships).
+
+### P4 — Release infrastructure (no audit)
+
+`CHANGELOG.md`, `docs/MAINNET_DEPLOY_RUNBOOK.md`, `.github/workflows/release.yml`.
+Documentation + CI only.
+
+### P5 — Consolidate: auth + processor port + IDL sync (delta-audit)
+
+**Aligns the remaining processor + auth files with upstream so the slot-share
+strategy works end-to-end.**
+
+Files (all byte-identical with upstream after this phase, except where noted):
+- `program/src/auth/secp256r1/{mod,webauthn,introspection}.rs` — port from
+  upstream. Replaces older typeAndFlags-format auth (which reconstructed
+  clientDataJSON server-side) with the format that embeds full raw
+  clientDataJSON in the auth payload. **Byte-identical with upstream.**
+- `program/src/processor/{create_wallet,manage_authority,transfer_ownership,
+  execute_deferred,revoke_session}.rs` — port from upstream. Brings authority
+  data layout to:
+  `Secp256r1 authority = header(48) + cred_hash(32) + pubkey(33) + rpIdHash(32) = 145B`
+  (previously variable-length raw rpId; now precomputed SHA256 digest at
+  offset 113, saves one syscall per Execute). **Byte-identical with upstream.**
+- `program/src/instruction.rs` — Shank IDL declarations resynced from
+  upstream (account metadata: writable modifiers, positions, descriptions);
+  5 fee instruction variants (disc 10–14) stripped. Runtime not affected
+  (sdk-legacy uses hand-written builders, not generated IDL).
+
+**Audit ask (P5):** Since these files are byte-identical with upstream,
+confirm Accretion's prior review of the upstream files extends to this
+program. Specifically:
+- Auth payload format change (typeAndFlags → embedded clientDataJSON) — was
+  this reviewed in the upstream audit? Any concerns specific to program-v2
+  context?
+- Authority layout change (raw rpId → rpIdHash) — same question.
+
+---
+
+## Files NOT changed since baseline (sanity)
+
+- `program/src/auth/ed25519.rs` — unchanged
+- `program/src/auth/mod.rs` — unchanged
+- `program/src/auth/traits.rs` — unchanged
+- `program/src/utils.rs` — unchanged
+- `program/src/state/wallet.rs` — unchanged (verified byte-identical with
+  upstream — wallet account layout is the cross-binary contract for
+  slot-share)
+- `program/src/state/authority.rs` — unchanged (same reasoning as wallet)
+- `program/src/state/deferred.rs` — unchanged
+- `program/src/processor/authorize.rs` — unchanged
+- `program/src/processor/reclaim_deferred.rs` — unchanged
+- `program/src/entrypoint.rs` — unchanged dispatch (still discs 0–9)
+
+---
+
+## Strip surface — what's NOT in `program-v2`
+
+Per the slot-share strategy, the following are intentionally absent:
+
+- `program/src/state/protocol_config.rs` — admin + fee config
+- `program/src/state/integrator_record.rs` — FeeRecord
+- `program/src/state/treasury_shard.rs` — treasury
+- `program/src/processor/protocol/{initialize_protocol,update_protocol,
+  register_integrator,withdraw_treasury,initialize_treasury_shard}.rs`
+- Discriminators 10–14 in entrypoint dispatch
+- `try_collect_fee` function in entrypoint
+- `ProtocolError` enum (codes 4001–4007)
+- `ProtocolConfig` / `FeeRecord` / `TreasuryShard` discriminator slots (5/6/7)
+  in `state/mod.rs::AccountDiscriminator`
+
+`scripts/check-no-fee.sh` enforces this via `scripts/fee-paths.txt`. CI fails
+on any introduction. Verified clean at `audit-pending-v1`.
+
+---
+
+## What we want from this engagement
+
+Specific questions for Accretion:
+
+1. **P1 action enforcement** — is the `evaluate_pre_actions` /
+   `evaluate_post_actions` engine + integration into `execute.rs` and
+   `create_session.rs` introducing any new vulnerabilities the prior audit
+   didn't cover? Action discriminator collision, integer overflow in
+   recurring-limit window math, race conditions between snapshot/execute,
+   vault invariant gaps?
+
+2. **P5 auth port** — confirm the typeAndFlags → embedded-clientDataJSON
+   format change is safe in this context. Particular attention to:
+   - origin field validation (intentionally omitted — see [audit doc L1
+     comment](../../program/src/auth/secp256r1/mod.rs))
+   - challenge field base64url encoding/decoding round-trip
+   - rpIdHash computation timing
+
+3. **P5 authority layout change** — confirm the raw rpId → rpIdHash storage
+   change preserves all binding properties. Specifically that the on-chain
+   stored rpIdHash remains tied to the credential at registration.
+
+4. **Slot-share compatibility** — given program-v2 will live at
+   `LazorjRF…` mainnet slot and later be replaced in-place by
+   `lazorkit-protocol`'s commercial binary, confirm:
+   - State account layouts are forward-compatible (existing Wallet,
+     Authority, Session, DeferredExec accounts created by program-v2 are
+     readable + valid for the commercial binary)
+   - Auth verification continues working for sessions/wallets created
+     pre-swap
+
+5. **Anything Accretion flagged in the prior audit that may have regressed**
+   — full diff bundle at [program-src.diff](./program-src.diff) for
+   line-by-line review.
+
+---
+
+## Deliverables included
+
+- [DELTA_BRIEF.md](./DELTA_BRIEF.md) (this file)
+- [program-src.diff](./program-src.diff) — full unified diff of `program/`
+  between the two tags (~5600 lines)
+- [program-src.diff.stat](./program-src.diff.stat) — per-file changed-line
+  counts
+- [upstream-parity.txt](./upstream-parity.txt) — byte-identity report vs
+  `lazorkit-protocol`
+- Git tags `audit-baseline-2026-02-accretion` (commit `d1eaaeb`) and
+  `audit-pending-v1` (commit `9c97fe2`)
+- This brief is intended to be sent alongside the on-chain `security_txt!`
+  pointer to the prior PDF.
+
+## Out of scope for this brief
+
+- `tests-sdk/`, `sdk/`, `docs/`, `scripts/`, `.github/`, `Cargo.toml`,
+  `assertions/Cargo.toml` — non-program changes (test infrastructure, build
+  config). Available in the full `git diff audit-baseline-2026-02-accretion..audit-pending-v1`
+  if Accretion requests but not part of the on-chain audit ask.
+- Operational items (mainnet deploy, multisig setup, binary swap procedure)
+  — handled in [docs/MAINNET_DEPLOY_RUNBOOK.md](../MAINNET_DEPLOY_RUNBOOK.md).
+
+---
+
+## Build reproducibility
+
+```bash
+git checkout audit-pending-v1
+cd program && cargo build-sbf --features mainnet
+shasum -a 256 ../target/deploy/lazorkit_program.so
+# Hash should match the artifact in the eventual mainnet deploy.
+```
+
+CI workflow at `.github/workflows/release.yml` reproduces and publishes the
+hash on each tag push.
+
+---
+
+## Contact
+
+- Email: security@lazorkit.app
+- GitHub Security Advisories: https://github.com/lazor-kit/program-v2/security/advisories/new
+- On-chain pointer: `solana program show LazorjRFNavitUaBu5m3WaNPjU1maipvSW2rZfAFAKi`
+  → `security_txt!` block links to this repo + audit PDF.