chore(codegen): split crates/perry-codegen/src/lower_call.rs (11.8k lines, lower_call + extract_options_fields) #1099

Part of #1097.

Current state

crates/perry-codegen/src/lower_call.rs is 11,796 lines with only ~19 top-level functions. A sibling lower_call/ subdir already exists with builtin.rs, native.rs, ui_styling.rs — so the precedent is set, the trunk just hasn't kept moving.

Distribution of the largest functions:

• lower_call — lines 642 → 3693 (~3.0k)
• lower_new — lines 3693 → 4480 (~787)
• apply_field_initializers_recursive — 4480 → 4759
• extract_options_fields — 4759 → 11366 (~6.6k) — by far the worst
• Native-module-table iteration helpers — 11439 → end

extract_options_fields is doing far more than its name suggests — it's the "look at this options object literal and decide what to do" mega-helper.

Proposed split

Continue populating crates/perry-codegen/src/lower_call/:

• lower_call/mod.rs — keep pub(crate) fn lower_call dispatcher only; each major branch delegates
• lower_call/new.rs — lower_new + apply_field_initializers_recursive
• lower_call/options.rs — extract_options_fields (split internally; see below)
• lower_call/buffer_intrinsic.rs — classify_buffer_numeric_read, try_emit_buffer_read_intrinsic, BufferNumericReadSpec (lines 70–297)
• lower_call/method_override.rs — emit_own_method_override_check
• lower_call/jsx.rs — decode_jsx_intrinsic_sentinel, split_children_from_props, try_rewrite_perry_tui_jsx_intrinsic, rewrite_jsx_box, rewrite_jsx_text, is_jsx_call_callee, fold_string_concat (lines 419–642)
• lower_call/native_table.rs — iter_native_module_table, arg_kinds_for, arg_kind_tag, ret_kind_tag, find_outer_writes_expr (lines 11366–end)

extract_options_fields (6.6k lines)

Open in a fresh file and look for the natural seams — almost certainly one branch per native API surface (fastify, ws, redis, mysql2, fs, http, child_process, etc.). Each can become a dedicated lower_call/options/<surface>.rs with a small dispatch table in lower_call/options/mod.rs. This is the largest single win on the file and the most subjective — leave room for the author to discover the right seams when they get into it.

Acceptance

Same conventions as the umbrella (#1097): pure moves, re-exports for stability, full test + parity suite green.