fix(0114): gate alias-qualified calls to one-level carry, pin to target

The lowerCall namespace branch routed alias.fn() through the global
qualified registration (first-wins) at any import depth, and through the
global last-wins bare map for comptime/generic members. Plain-identifier
alias roots now resolve via the carry-aware namespaceAliasVerdict:

- visible alias (own edge or ONE flat hop): the member dispatches the
  TARGET module's own fn (namespaceFnMember + fd-keyed bareAuthorFuncId),
  so two modules' same-named aliases each call their own target.
- two direct flat imports carrying the alias to distinct targets:
  loud ambiguity diagnostic.
- alias only reachable beyond one hop: "namespace 'X' is not visible".
- foreign / builtin / #compiler members keep the literal-symbol path.

Regressions: examples 0832 (two-hop), 0833 (carried collision),
0834 (own-target pin / first-wins repair).

examples/0833-modules-namespace-alias-carried-collision-ambiguous.sx

@@ -0,0 +1,15 @@
+// Two direct flat imports each declare the SAME alias name `t` pointing at
+// DIFFERENT targets. Using the carried alias here is ambiguous and rejected
+// loudly — never a silent first-registration pick. (Each module's own use
+// of its own `t` stays valid — see 0834.)
+//
+// Regression (issue 0114): collisions used to resolve silently first-wins
+// through the global qualified-fn registration.
+
+#import "modules/std.sx";
+#import "0833-modules-namespace-alias-carried-collision-ambiguous/a.sx";
+#import "0833-modules-namespace-alias-carried-collision-ambiguous/b.sx";
+
+main :: () {
+    print("{} {} {}\n", use_a(), use_b(), t.fx());
+}