JVM-semantics fixes and small cleanups

- take-last / drop-last return seqs, not vectors: take-last wraps in seq; drop-last
  is the JVM (map (fn [x _] x) coll (drop n coll)) form (lazy, () when empty).
- cycle is lazy ((lazy-seq (concat coll (cycle coll)))) so it no longer counts its
  argument and terminates on a lazy/infinite input.
- fold's foldable-call catch uses :default, matching the rest of jolt-core and
  also catching a raw host condition from a folding primitive.
- alts! rejects non-channel ports with a clear error (put specs / :default are
  unsupported) instead of crashing inside ac-poll!.
- Misc: drop the unreachable second getCause clause; jolt-nth on a string raises
  'nth "index out of bounds" like the vector branch; name the inline fixpoint cap;
  bld-sh-capture rejoins lines with newlines; clarify a couple of comments.

jolt-core/jolt/analyzer.clj

@@ -32,6 +32,10 @@
 
 (declare analyze)
 
+;; Special forms analyze-special has a dispatch arm for — the subset of the host
+;; contract's reserved words (jolt.host/form-special?) the analyzer lowers itself.
+;; The two differ deliberately (e.g. interop heads like `new`/`.` are reserved but
+;; analyzed in analyze-list), so keep them in sync by intent, not by equality.
 (def ^:private handled
   #{"quote" "if" "do" "def" "fn*" "let*" "loop*" "recur" "throw" "try"
     "syntax-quote" "var" "letfn" "set!" "defmacro"})