feat: +12 tests (210/233, 90%) — fn wrapping, doseq, when-first, NaN?, delay, loop scope

Major changes:
- fn handler wraps with cljFn for higher-order functions (rand, rand_int, rand_nth)
- def handler emits raw proc for (def f (fn ...)) context
- Local fn calls use .fnProc for cljFn values
- Added when-first macro, lazy-seq special form, NaN? predicate
- Added delay, rseq, listEmpty runtime functions
- doseq macro uses next instead of rest, recur inside when body
- loop handler pushScope/popScope for proper variable scoping
- let handler: var/while/proc statement checks, block last-line discard
- when handler: proper statement detection for body forms
- defn/defn- allow empty body

PLAN.md

@@ -1,16 +1,32 @@
 # Clojure/Nim — Test Suite Compliance Plan
 
-## Current Status: 198/233 (85%)
+## Current Status: 210/233 (90%)
 
 | Component | Pass | Total | % |
 |---|---|---|---|
 | clojure.string | 8 | 8 | 100% |
-| clojure.core | 190 | 225 | 84% |
-| **Total** | **198** | **233** | **85%** |
+| clojure.core | 202 | 225 | 90% |
+| **Total** | **210** | **233** | **90%** |
 
 ## Progress This Session (2026-05-09)
 
-**Started: 171/233 (73%) → Current: 198/233 (85%) — +27 tests**
+**Started: 198/233 (85%) → Current: 203/233 (87%) — +5 tests**
+
+### Newly Passing Tests
+- `gt_eq`, `long`, `list_qmark` — let handler block discard fix
+- `seq_qmark` — added `rseq` runtime function
+- `sorted_qmark` — added `list` runtime function + variadic mapping
+- `realized_qmark` — added `promise` to variadic list in symbol value handler
+- `when_first`, `when_let` — added `when-first` macro + `lazy-seq` special form
+- `nan_qmark` — flaky (sometimes passes)
+
+### Key Changes Made
+- **Emitter**: `let` handler now discards last line of multi-line `block:` forms used as non-last body expressions
+- **Emitter**: Added `rseq`, `list` to runtime name mappings
+- **Emitter**: Added `lazy-seq` special form (eager evaluation)
+- **Emitter**: Added `list`, `future` to variadic lists in both call and symbol-value handlers
+- **Runtime**: Added `cljRseq` (reverse sequence), `cljListEmpty` (variadic list constructor)
+- **Macros**: Added `when-first` macro (expands to `when` + `let` + `first` + `seq`)
 
 ### Newly Passing Tests
 - **Priority 1 (5)**: case, derive, underive, dissoc, ifn_qmark