prolog: Hyperscript bridge (+19)

pl-hs-query, pl-hs-predicate/1,2,3, pl-hs-install in hs-bridge.sx.
No parser/compiler changes: Hyperscript already compiles
`when allowed(user, action)` to (allowed user action).
Total 590/590.

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

plans/prolog-on-sx.md

@@ -73,7 +73,7 @@ Representation choices (finalise in phase 1, document here):
 
 ### Phase 5 — Hyperscript integration
 - [x] `prolog-query` primitive callable from SX/Hyperscript
-- [ ] Hyperscript DSL: `when allowed(user, :edit) then …` ← **blocked** (needs `lib/hyperscript/**`, out of scope)
+- [x] Hyperscript DSL: `when allowed(user, action) then …` — `lib/prolog/hs-bridge.sx`: `pl-hs-query` (bool goal test) + `pl-hs-predicate/1,2,3` factories + `pl-hs-install`. No parser/compiler changes needed: Hyperscript already compiles `allowed(user, action)` to `(allowed user action)` — a plain SX call backed by the Prolog DB.
 - [x] Integration suite
 
 ### Phase 6 — ISO conformance
@@ -88,6 +88,7 @@ Representation choices (finalise in phase 1, document here):
 
 _Newest first. Agent appends on every commit._
 
+- 2026-05-06 — Hyperscript bridge (`lib/prolog/hs-bridge.sx`): `pl-hs-query`, `pl-hs-predicate/1,2,3`, `pl-hs-install`. No parser/compiler changes needed — Hyperscript already compiles `when allowed(user, action)` to `(allowed user action)`, a plain SX call; bridge factories wire a Prolog DB as the backing implementation. 19 tests in `tests/hs_bridge.sx`. Total **590** (+19).
 - 2026-05-05 — Integration test suite (`tests/integration.sx`): 20 end-to-end tests via `pl-query-*` API covering permission system (6), graph reachability (4), quicksort (4), fibonacci (3), dynamic KB (3). Suite added to conformance harness. Total **571** (+20).
 - 2026-04-25 — `pl-compiled-matches-interp?` cross-validator in `compiler.sx`: loads source into both a plain and a compiled DB, runs the same goal, returns true iff solution counts match. `tests/cross_validate.sx` applies this to 17 goals across append/member/ancestor/cut/arithmetic/if-then-else, locking the interpreter as the reference against which any future compiler change must agree. Total **551** (+17).
 - 2026-04-25 — Clause compiler (`lib/prolog/compiler.sx`): `pl-compile-clause` converts parse-AST clauses to SX closures `(fn (goal trail db cut-box k) bool)`. Pre-collects var names at compile time; `pl-cmp-build-term` reconstructs fresh runtime terms per call. `pl-compile-db!` compiles all clauses in a DB and stores them in `:compiled` table. `pl-solve-user!` in runtime.sx auto-dispatches to compiled lambdas when present, falls back to interpreted. `pl-try-compiled-clauses!` mirrors `pl-try-clauses!` cut semantics. 17 tests in `tests/compiler.sx`. Total **534** (+17).