Implement the full count loop compiler, replacing the stubs in count.rs,
count_any.rs, and count_bindings.rs with a single consolidated module.
Handles both field-based and value-based count nodes. Field counts walk
the resource via resolve_alias_path then iterate the wildcard array;
value counts operate on an arbitrary collection expression.
For nested wildcard paths like A[*].B[*].C, the compiler emits recursive
ForEach loops, drilling one wildcard level at a time. When an outer
count binding already covers a prefix, the inner loop starts from the
bound element register instead of re-walking from the resource root.
Existence patterns (count > 0, count == 0) are recognized and lowered
to LoopMode::Any, which exits on the first match rather than counting
every element.
Count-binding resolution threads the current-element register through
inner field references and current() calls so that nested conditions
can address fields relative to the loop variable.
Also fixes the bound_len arithmetic in conditions_wildcard.rs with a
cleaner strip_prefix call, and removes the nested-wildcard bail in
split_count_wildcard_path since the compiler now handles them.
