core: one alias store (jolt-ark); '.' classified as the special form it is

require-:as wrote the string-keyed :imports table (which resolution reads)
while ns-aliases read the symbol-keyed :aliases table (which nothing wrote)
— so (ns-aliases) was always empty and the alias fn had to write both as a
bridge. :aliases (alias-name string -> ns-name string) is THE store now:
require :as and the alias fn write it, both resolution paths read it first
(falling back to :imports for class imports, which is all that table holds
now), ns-unalias removes one entry, and ns-aliases presents Clojure's
{alias-symbol -> namespace object} shape built from it. ns-resolve's
qualified path goes through the same lookup.

Also: the coverage dashboard's last 'resolvable-not-interned' entry was '.'
— which (resolve '.) returns nil for on the JVM too; the tool now classifies
it as the special form it is, and that category reads ZERO.

7 new unified-alias spec rows (require/alias/ns-unalias round-trips through
both the resolution and introspection views); the white-box namespace test
tracks the accessor rename. Gate exit 0.

test/integration/namespace-test.janet

@@ -47,7 +47,7 @@
   (assert (= "my.app" (ctx-current-ns ctx)) "ns with require sets current namespace")
   # Alias should be registered
   (let [ns (ctx-find-ns ctx "my.app")
-        aliased (ns-import-lookup ns "o")]
+        aliased (ns-alias-lookup ns "o")]
     (assert (= "other.lib" aliased) "alias o -> other.lib registered")))
 (print "  passed")
 
@@ -55,7 +55,7 @@
 (let [ctx (fresh-ctx)]
   (eval-form ctx @{} (parse-string "(require '[other.lib :as o])"))
   (let [ns (ctx-find-ns ctx "user")
-        aliased (ns-import-lookup ns "o")]
+        aliased (ns-alias-lookup ns "o")]
     (assert (= "other.lib" aliased) "standalone require registers alias")))
 (print "  passed")