core: fix jolt-265 — syntax-quote fully-qualifies core syms to clojure.core/ (#18)

Re-attempt of the deferred gap, now unblocked. The earlier uberscript break
wasn't qualification itself but an aliased-ref resolution bug it exposed:
resolve-var looked up ns-aliases (e.g. g/foo) against the analyzer's REBOUND
ctx-current-ns (jolt.analyzer, since the analyzer runs interpreted in its own
ns) instead of the namespace being compiled. A user's aliased refs failed
mid-compile (g/hello -> nil in the bundled standalone).

- resolve-var resolves aliases against :compile-ns when set (same ns
  h-current-ns uses), falling back to ctx-current-ns — correct for both modes.
- sq-symbol qualifies a resolved clojure.core name to clojure.core/<name>
  (Clojure hygiene); special forms stay bare; unresolved syms -> current ns.

Tests updated to the qualified behavior (features-test, reader-forms-spec).

Co-authored-by: Yogthos <yogthos@gmail.com>

test/integration/features-test.janet

@@ -82,7 +82,8 @@
    ["macroexpand-1"      "true"        "(do (defmacro mm [x] (list 'inc x)) (= '(inc 5) (macroexpand-1 '(mm 5))))"]
    ["gensym distinct"    "false"       "(= (gensym) (gensym))"]
    ["syntax-quote splice" "[1 2 3]" "(let [xs [1 2 3]] `[~@xs])"]
-   ["syntax-quote unquote" "(quote (+ 1 5))" "(let [x 5] `(+ 1 ~x))"]
+   # syntax-quote fully-qualifies resolved core symbols to clojure.core/ (jolt-265).
+   ["syntax-quote unquote" "(quote (clojure.core/+ 1 5))" "(let [x 5] `(+ 1 ~x))"]
 
    ### 8. Recursion
    ["recursion fact"     "120"         "(do (defn fact [n] (if (<= n 1) 1 (* n (fact (dec n))))) (fact 5))"]