issue 0151 RESOLVED: infer generic $T through generic-struct / pointer / UFCS-pack params

The generic-inference engine could not bind a $T from a generic-struct
argument head. Four gaps, all on the inference + UFCS dispatch path:

- extractTypeParam / matchTypeParam(Static) gained a parameterized_type_expr
  arm: recover the arg instance's recorded per-param bindings
  (struct_instance_bindings + the template's ordered type_params via
  struct_instance_author) and recurse positionally, so $T binds from
  Box($T) <=> Box(i64) like it does from []$T <=> []i64. This also fixes
  the pointer case — *Box($T) recurses into its Box($T) pointee.
- The pointer_type_expr arm now falls through to match the pointee against a
  non-pointer arg (auto-address-of: a *Box($T) param accepts a by-value
  Box($T), e.g. the UFCS receiver b.m()).
- ExprTyper.inferType gained a .lambda arm building the closure type from the
  lambda's annotations, so the UFCS binder (which types args from the raw AST
  before they are lowered) can bind a Closure(..) -> $R from the worker's
  declared return type.
- A pack UFCS target (worker: Closure(..) -> $R, ..$args) now routes through
  the same lowerPackFnCall the direct call uses, with the receiver spliced in
  as args[0] (lowerPackFnCall reads only call_node.args, never the callee).

Regression tests: examples/0214 (direct + UFCS closure-return pack) and
examples/0215 (by-value / pointer / multi-param / nested / UFCS-auto-ref
generic-struct-head inference). Suite green 728/0.

examples/expected/0214-generics-ufcs-closure-return-pack.exit

@@ -0,0 +1 @@
+0

examples/expected/0214-generics-ufcs-closure-return-pack.stderr

@@ -0,0 +1 @@
+

examples/expected/0214-generics-ufcs-closure-return-pack.stdout

@@ -0,0 +1,2 @@
+direct=42
+ufcs=42

examples/expected/0215-generics-infer-through-pointer.exit

@@ -0,0 +1 @@
+0

examples/expected/0215-generics-infer-through-pointer.stderr

@@ -0,0 +1 @@
+

examples/expected/0215-generics-infer-through-pointer.stdout

@@ -0,0 +1,5 @@
+unbox=42
+byval=42
+second=2.500000
+nested=9
+ufcs=42