ci(chapel): unblock Compile Chapel Metalayer + Build & Test Zig FFI Bridge (#131)

## Summary

Fixes two pre-existing, independent breakages that have kept `Chapel
Accelerator CI` red on every run since it was first authored
(2026-04-20, commit e44815a) — zero successes in the 100-run history.

| Job | Symptom | Root cause | Fix |
|---|---|---|---|
| `Compile Chapel Metalayer` | `chapel_ffi_exports.chpl:29: syntax
error: near '{'` (cascading into parallel_proof_search.chpl) | `extern
\"C\" { ... }` is Chapel's "extern blocks" feature, requiring Chapel
built with LLVM + clang headers. The official
`chapel-2.3.0-1.ubuntu24.amd64.deb` is not. | Drop the wrapper. The 35
prover-id / category-id `c_int` constants are also `#define`d in
`src/zig_ffi/chapel_ffi_exports.h` — that's the canonical source for any
non-Chapel consumer. The Chapel copies only need module-level scope. |
| `Build & Test Zig FFI Bridge` | `build.zig:23: no field or member
function named 'addLibrary' in 'Build'` | `build.zig` line 1 declares
"Compatible with Zig 0.14+/0.15+" and uses the unified
`Build.addLibrary` API. Workflow pinned `mlugg/setup-zig@… with:
version: 0.13.0`. | Bump the two `version: 0.13.0` lines in
chapel-ci.yml to `0.14.0` (matches what build.zig declares). |

## Test plan

- [ ] CI: `Compile Chapel Metalayer` returns success on this branch.
- [ ] CI: `Build & Test Zig FFI Bridge` returns success on this branch.
- [ ] CI: `Rust Build with Chapel Feature` (Job 3) actually runs (was
previously skipped because Job 2 failed).

## Note on scope

None of these are required checks; this PR doesn't unblock anything
blocking the merge queue. It makes Chapel L2.1 actually CI-verifiable
for the first time — `handover/TODO.md`'s "L2.1 ✅ Done" status was based
on local builds only.

Surfaced during the 2026-05-30 dependabot-deadlock triage (alongside PR
#128 + PR #130).

Author: hyperpolymath

.github/workflows/chapel-ci.yml

@@ -86,7 +86,7 @@ jobs:
       - name: Install Zig
         uses: mlugg/setup-zig@d1434d08867e3ee9daa34448df10607b98908d29 # v2.2.1
         with:
-          version: 0.13.0
+          version: 0.14.0
 
       - name: Build Zig FFI library (with Chapel stubs)
         run: cd src/zig_ffi && zig build -Doptimize=ReleaseSafe
@@ -151,7 +151,7 @@ jobs:
       - name: Install Zig
         uses: mlugg/setup-zig@d1434d08867e3ee9daa34448df10607b98908d29 # v2.2.1
         with:
-          version: 0.13.0
+          version: 0.14.0
 
       - name: Install Rust
         uses: dtolnay/rust-toolchain@4be9e76fd7c4901c61fb841f559994984270fce7 # stable

src/chapel/chapel_ffi_exports.chpl

@@ -26,57 +26,63 @@ extern record CProofResult {
 // Prover ID constants (match ProverInfo.id and Zig ProverKind enum)
 // ---------------------------------------------------------------------------
 
-extern "C" {
-    // Interactive proof assistants
-    const PROVER_AGDA: c_int      = 0;
-    const PROVER_COQ: c_int       = 1;
-    const PROVER_LEAN: c_int      = 2;
-    const PROVER_ISABELLE: c_int  = 3;
-    const PROVER_IDRIS2: c_int    = 4;
-    const PROVER_FSTAR: c_int     = 5;
-    const PROVER_HOL4: c_int      = 6;
-    const PROVER_HOLLIGHT: c_int  = 7;
-    const PROVER_NUPRL: c_int     = 8;
-    const PROVER_MINLOG: c_int    = 9;
-
-    // SMT solvers
-    const PROVER_Z3: c_int        = 10;
-    const PROVER_CVC5: c_int      = 11;
-    const PROVER_ALTERGO: c_int   = 12;
-
-    // First-order ATPs
-    const PROVER_VAMPIRE: c_int   = 13;
-    const PROVER_EPROVER: c_int   = 14;
-    const PROVER_SPASS: c_int     = 15;
-
-    // Declarative provers
-    const PROVER_METAMATH: c_int  = 16;
-    const PROVER_MIZAR: c_int     = 17;
-    const PROVER_PVS: c_int       = 18;
-    const PROVER_ACL2: c_int      = 19;
-    const PROVER_TLAPS: c_int     = 20;
-    const PROVER_TWELF: c_int     = 21;
-    const PROVER_IMANDRA: c_int   = 22;
-
-    // Auto-active verifiers
-    const PROVER_DAFNY: c_int     = 23;
-    const PROVER_WHY3: c_int      = 24;
-
-    // Constraint solvers
-    const PROVER_GLPK: c_int      = 25;
-    const PROVER_SCIP: c_int      = 26;
-    const PROVER_MINIZINC: c_int  = 27;
-    const PROVER_CHUFFED: c_int   = 28;
-    const PROVER_ORTOOLS: c_int   = 29;
-
-    // Category constants
-    const CATEGORY_INTERACTIVE: c_int  = 0;
-    const CATEGORY_SMT: c_int          = 1;
-    const CATEGORY_ATP: c_int          = 2;
-    const CATEGORY_DECLARATIVE: c_int  = 3;
-    const CATEGORY_AUTOACTIVE: c_int   = 4;
-    const CATEGORY_CONSTRAINT: c_int   = 5;
-}
+// (Was originally `extern "C" { ... }`, but Chapel's extern-blocks feature
+// requires a Chapel install built with LLVM + clang headers; the official
+// `chapel-2.3.0-1.ubuntu24.amd64.deb` used in `chapel-ci.yml` is not. The
+// canonical C-visible copy lives in `src/zig_ffi/chapel_ffi_exports.h`
+// (`#define PROVER_AGDA 0`…), which is what every non-Chapel consumer
+// reads; the constants below only need module-level scope inside Chapel.
+// Keep the two copies in sync if values change.)
+
+// Interactive proof assistants
+const PROVER_AGDA: c_int      = 0;
+const PROVER_COQ: c_int       = 1;
+const PROVER_LEAN: c_int      = 2;
+const PROVER_ISABELLE: c_int  = 3;
+const PROVER_IDRIS2: c_int    = 4;
+const PROVER_FSTAR: c_int     = 5;
+const PROVER_HOL4: c_int      = 6;
+const PROVER_HOLLIGHT: c_int  = 7;
+const PROVER_NUPRL: c_int     = 8;
+const PROVER_MINLOG: c_int    = 9;
+
+// SMT solvers
+const PROVER_Z3: c_int        = 10;
+const PROVER_CVC5: c_int      = 11;
+const PROVER_ALTERGO: c_int   = 12;
+
+// First-order ATPs
+const PROVER_VAMPIRE: c_int   = 13;
+const PROVER_EPROVER: c_int   = 14;
+const PROVER_SPASS: c_int     = 15;
+
+// Declarative provers
+const PROVER_METAMATH: c_int  = 16;
+const PROVER_MIZAR: c_int     = 17;
+const PROVER_PVS: c_int       = 18;
+const PROVER_ACL2: c_int      = 19;
+const PROVER_TLAPS: c_int     = 20;
+const PROVER_TWELF: c_int     = 21;
+const PROVER_IMANDRA: c_int   = 22;
+
+// Auto-active verifiers
+const PROVER_DAFNY: c_int     = 23;
+const PROVER_WHY3: c_int      = 24;
+
+// Constraint solvers
+const PROVER_GLPK: c_int      = 25;
+const PROVER_SCIP: c_int      = 26;
+const PROVER_MINIZINC: c_int  = 27;
+const PROVER_CHUFFED: c_int   = 28;
+const PROVER_ORTOOLS: c_int   = 29;
+
+// Category constants
+const CATEGORY_INTERACTIVE: c_int  = 0;
+const CATEGORY_SMT: c_int          = 1;
+const CATEGORY_ATP: c_int          = 2;
+const CATEGORY_DECLARATIVE: c_int  = 3;
+const CATEGORY_AUTOACTIVE: c_int   = 4;
+const CATEGORY_CONSTRAINT: c_int   = 5;
 
 // ---------------------------------------------------------------------------
 // Helpers