feat: #get property accessors (no-paren method-as-field)

A method declared `name :: (self: *T) -> R #get => expr;` is invoked via
no-paren field syntax (`obj.name`) instead of `obj.name()`. It is an ordinary
method (registered `Type.method`, flagged is_get); field-access lowering and
inference dispatch to it when no real field of that name exists, by synthesizing
a no-arg `obj.name()` call routed through the normal call path (so receiver
address-of and generic binding are reused).

- Lexer/token: `#get`. Parser: parsed after the return type in parseFnDecl;
  hasFnBodyAfterArrow treats it as a body marker so struct-body methods parse.
- Resolution: getAccessorFor handles a generic-struct instance and a plain
  struct. A REAL field of the same name wins (a getter never shadows stored
  data). An explicit postfix-deref receiver (`p.*.getter`) dispatches on the
  inner pointer so it takes the working auto-deref path.
- Works on plain + generic structs (incl. getters returning the type param),
  in expressions/conditions/args/loop-bounds, chained, and via a pointer
  receiver. Examples: types/0196 (basic) + types/0197 (stress).

Known narrow limitations (clean errors / workarounds, not silent): a getter
RESULT used directly as a method/getter receiver (`o.gi.dbl`) errors — bind it
to a local first; a getter named `len`/`ptr` returning non-i64 mis-infers
(the .len/.ptr builtin-field shortcut).

src/ir/lower/expr.zig

@@ -637,6 +637,30 @@ pub fn lowerFieldAccess(self: *Lowering, fa: *const ast.FieldAccess, span: ast.S
         return self.lowerObjcDefinedStateFieldRead(fa.object, info);
     }
 
+    // `#get` property accessor: `obj.field` where `field` is a `#get` method
+    // dispatches as a no-paren method call (`obj.field()`). Detected via type
+    // info only (no lowering) so the receiver is not evaluated twice — the
+    // synthesized call re-lowers `fa.object` and handles the receiver
+    // address-of + any generic binding itself.
+    {
+        var recv_ty = self.inferExprType(fa.object);
+        if (!recv_ty.isBuiltin()) {
+            const di = self.module.types.get(recv_ty);
+            if (di == .pointer) recv_ty = di.pointer.pointee;
+        }
+        if (self.getAccessorFor(recv_ty, fa.field) != null) {
+            // For an explicit-deref receiver `(*p).getter`, dispatch on the
+            // inner pointer `p` (`p.getter`, auto-deref) — semantically identical
+            // and it takes the working receiver path (the synthesized call on a
+            // `.deref_expr` receiver otherwise mis-lowers the `*self` address).
+            var recv_fa = fa.*;
+            if (fa.object.data == .deref_expr) recv_fa.object = fa.object.data.deref_expr.operand;
+            const callee_node = Node{ .data = .{ .field_access = recv_fa }, .span = span };
+            const syn_call = ast.Call{ .callee = @constCast(&callee_node), .args = &.{} };
+            return self.lowerCall(&syn_call);
+        }
+    }
+
     var obj = self.lowerExpr(fa.object);
     var obj_ty = self.inferExprType(fa.object);
 
@@ -825,6 +849,38 @@ pub fn vectorLaneIndex(field: []const u8) ?u32 {
     return null;
 }
 
+/// A `#get` property accessor for `obj_ty.field`, or null. A `#get` method is a
+/// normal method (registered `Type.method`) marked `is_get`; it is reachable via
+/// no-paren field syntax. Handles a generic-struct instance (`List(i64).len`)
+/// and a plain struct (`Foo.bar`). `ty` must be the dereferenced (non-pointer)
+/// receiver type.
+pub fn getAccessorFor(self: *Lowering, ty: TypeId, field: []const u8) ?*const ast.FnDecl {
+    if (ty.isBuiltin()) return null;
+    // A REAL field of this name wins over a same-name `#get` (a getter must not
+    // shadow stored data on the read path). If the struct genuinely declares the
+    // field, this is not a property access.
+    const field_id = self.module.types.internString(field);
+    for (self.getStructFields(ty)) |f| {
+        if (f.name == field_id) return null;
+    }
+    // Generic instance: genericInstanceMethod is keyed by the instance name
+    // (e.g. "List(i64)"), which is what formatTypeName produces.
+    const tn = self.formatTypeName(ty);
+    if (self.genericInstanceMethod(tn, field)) |m| {
+        return if (m.fd.is_get) m.fd else null;
+    }
+    // Plain struct: methods are registered "StructName.method" in fn_ast_map.
+    const info = self.module.types.get(ty);
+    if (info == .@"struct") {
+        const sname = self.module.types.getString(info.@"struct".name);
+        const q = std.fmt.allocPrint(self.alloc, "{s}.{s}", .{ sname, field }) catch return null;
+        if (self.program_index.fn_ast_map.get(q)) |fd| {
+            return if (fd.is_get) fd else null;
+        }
+    }
+    return null;
+}
+
 pub fn lowerFieldAccessOnType(self: *Lowering, obj: Ref, obj_ty: TypeId, field: []const u8, span: ast.Span) Ref {
     const field_name_id = self.module.types.internString(field);