docs(handover): update STATE + TODO for 2026-04-26 follow-up batch

- STATE.md: note all three interface crates build clean; add session log
  for graphql fix, FFI audit, bounded_read_config, F5 deferred
- TODO.md: add completed-items section; F5 (boj-server echidna-llm-mcp)
  flagged as deferred

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: hyperpolymath

docs/handover/STATE.md

@@ -4,7 +4,7 @@
 `ECHIDNA-TODO.md` (actionable backlog) and the full continuation
 prompts at `verification-ecosystem/echidna/docs/handover/`.
 
-Last updated: 2026-04-20.
+Last updated: 2026-04-26.
 
 ---
 
@@ -103,7 +103,7 @@ Also corrected 2026-04-19 (were mis-listed as "planned"):
 - **Optional**: Chapel (parallel proof dispatch).
 - **ABI**: Idris2 (7+ modules, zero `believe_me`).
 - **FFI**: Zig (4 shared libraries).
-- **Interfaces**: GraphQL (8081), gRPC (50051), REST (8000).
+- **Interfaces**: GraphQL (8081), gRPC (50051), REST (8000). All three interface crates build clean as of 2026-04-26.
 - **Build**: Justfile primary, Cargo workspace.
 - **Container**: Podman + Containerfile.
 
@@ -137,6 +137,13 @@ Also corrected 2026-04-19 (were mis-listed as "planned"):
 | `verification-ecosystem/echidna/.machine_readable/6a2/STATE.a2ml` | Session ledger incl. `[l3-status-after-wave-2]` + `[wave-3-handover-hints]` |
 | `verification-ecosystem/echidna/docs/handover/README.md` | Index + drift-handling policy |
 
+## Session log highlights (2026-04-26)
+
+- **echidna-graphql build fixed** (`5aec9d5`) — ProverKind enum expanded from 30 → 113 variants (exhaustive, no catch-all) across schema.rs + resolvers.rs + ffi_wrapper.rs; FfiProverBackend trait wired (config/set_config/search_theorems); FFI pointer casts corrected. `cargo build -p echidna-graphql` now clean.
+- **FFI boundary audit** (`b4d682b`) — `audits/audit-ffi-boundary.md` (4-section per-module safety review) + `audits/assail-classifications.a2ml` (7 classifications suppressing legitimate UnsafeCode at all three interface ffi_wrapper.rs files + core ffi/ + proof_search.rs). panic-attack findings drop from active to classified.
+- **bounded_read_config helper** — `src/rust/integrity/io.rs` ships sync 1 MiB-capped read helper; `solver_integrity.rs` migrated. Remaining UnboundedAllocation finding resolved.
+- **F5 deferred** — `boj-server` `echidna-llm-mcp` cartridge real invocation is the one remaining open item. BoJ currently operates in skeleton mode for this cartridge; echidna REST layer is fully wired to its boundary.
+
 ## Session log highlights (2026-04-19)
 
 - **Chapel FFI self-link fix** (`53ab9b8`) — `-Dstubs=true` default in `src/zig_ffi/build.zig`; `-fno-sanitize=undefined` flag; `use anyhow::Context;` in `proof_search.rs`. `cargo build --features chapel` now links standalone.

docs/handover/TODO.md

@@ -4,13 +4,20 @@
 we are) and the full continuation prompts at
 `verification-ecosystem/echidna/docs/handover/{L1,L2,L3,PRODUCTION-WIRING-PLAN}.md`.
 
-Last updated: 2026-04-20.
+Last updated: 2026-04-26.
 
 Execution order from the master plan: **L3 → L1 → L2.** L3 blocks L1;
 L1 blocks L2 (because Chapel consumes Cap'n Proto schemas).
 
 ---
 
+## Completed items (2026-04-26)
+
+- ✅ **`echidna-graphql` build** — ProverKind 30→113 variants, trait stubs, FFI casts fixed (`5aec9d5`). All three interface crates now build clean.
+- ✅ **FFI boundary audit** — `audits/audit-ffi-boundary.md` + `audits/assail-classifications.a2ml` classifying all legitimate UnsafeCode at FFI boundaries (`b4d682b`).
+- ✅ **`bounded_read_config`** — sync 1 MiB-capped read helper in `src/rust/integrity/io.rs`; `solver_integrity.rs` migrated.
+- ⏳ **F5 (boj-server `echidna-llm-mcp`)** — deferred to separate dispatch. BoJ in skeleton mode for this cartridge.
+
 ## P0 — Immediate pickup
 
 | Task | Lane | Est | Blocks |